Yep, I can relate, Rain.  I have always had similar fears.  Speaking in front of groups and playing live.  I have had to fight through them my entire life.  When I was asked to get involved in our Churches worship band, in the past I would always come up with excuses why I couldn't join and be a part of it.  
 
About 2 years ago, the Worship Leader put an extreme amount of pressure on me to get up there and play with the band.  In my last ditch effort to find another excuse, I told him I had not played live for 15 years and was completely out of practice for live playing.  He didn't take no for and answer and I ended up at a rehearsal/ practice.  I brought my electric guitar and my bass.  He really wanted me to play Electric Lead.  I am just not a natural Lead player.  With how nervous I was, even in front of a small group, I felt like I was terrible at the audition.  When I tried out at bass, I thought I nailed it.  He asked me which I preferred to play for my debut and I said Bass.  
 
I was sooooo extremely nervous the first Sunday I got up and played.  Each service usually seats 300-400 people.  I made a few mistakes through out the songs, but as Herb said, almost no one noticed.  In fact, the only 2 people that did notice were the other 2 alternate Bass players.  The rush you get playing live was incredible and I told the WL afterwards that I wanted to do it again; that I needed to do it again, and please don't wait too long to get me back up there, so I don't try to back out.  Now that I have been playing again for 2 years, every 2-3 weeks in rotation; it has become old hat, again.  I fear that if I stop, I will fall back into being reluctant to get up in front of crowds again.  
 
I still have never sang live in front of an audience.  I don't know that I could do that yet.  Reece has been pushing me to perform live in front of a songwriters group he belongs too.  Maybe, IDK.  That would be a huge step for me.  I would have to be well practiced to do so.  Maybe I would half to try the Beta Blockers to do that, Rain.  That is WAY out of my natural element.  Good to know they work, anyway.

I don't know if I will ever feel that I'm accomplished enough to play live in front of a crowd of strangers.  Other than a small handful of times where I played in a band (all from 1979-1984), I've only once been on stage with a guitar in my hands and, ironically, that was in Las Vegas!  It was for all of 15-20 seconds as part of a comedy gag.  The keyboard player from Poison (Stu Simone) created a parody band called Hair Guitar.  During one gig at a Vegas casino he needed replacement guitarists and hired two of my friends.  By a fun coincidence, I won my Regional darts competition to make me eligible for the Nationals and that just happened to be occurring the SAME WEEK!  So I left early to be their roadie from Sunday thru Wednesday, participated in the Nationals Thursday and Friday then played in a big tournament Saturday and Sunday (getting on stage for one event there as well!).  Needless to say, my performance anxiety was much worse with the darts where I was expected to perform.
 
I've also been a director of a non-profit organization for three years as well as the director of Oregon Open dart tournament for seven years (the oldest dart event in the nation).  That had me speaking to hundreds of people but I don't seem to have the public speaking fear that many do.  

I recently started on propranolol for essential tremor, which seems to affect one person in every generation in my family. Even a low dose (5 mg) makes a big difference. It means I don't have to worry about shaky fingers, which is part of a vicious cycle for nervousness in playing for other people. It can also help with phobias.
 
I've read that lots of serious musicians (without essential tremor) use it for performing.

I forgot to mention that instead of a couple of alcoholic drinks, one substitute that helps is B-12.  You can't take too much either since any extra just gets pissed away.

My CG teacher was told that Potassium helps so the guy would eat a bunch of bananas before a concert.  Yes you can touch my monkey....

Magnesium could also help as it's a great relaxant. Great for anxiety, restless legs, things like that. It also protects the hearing from noise damage so there's another music related bonus. 

Thanks for sharing. I will look into this, as i some how wants to perform again. Being a studio guy is cool, but people are asking me to perform live, now i cant, but maybe with some more meds!!!

Rain , go crescendo , i will talk about my experience decades ago as a performers at that time ( lyricist) , things that help me suer cool i am now :

1) booking and performing for training in the same condition but with some friends or college as public

2) working in a store during 12 years during my studies helped me a lot. Like crazy to handle stress , people handling , confidence ect ...

3) number 2 allowed me to quikly make a relationship with the public ( now students ) , crucial to smooth out the atmosphere by quik question , humour , stuff that " break the ice " when you will feel the public is cool , you will be also .... It s important that you lead the croud , you impose the rythm , they will fallow ....you will be then in your land ...

4) don t be afraid to make all you entourage including us , listen to your track , if you have positive feedback , you will be more selfconfident ....

5) said hundreds time , but see what s going on in the world , all the drama, then think that we re luky , and streessing for some that is for fun like that doesn t make sens ....

One experience that was tuff for us was a first live radio .... But i stressed all my bro s to keep it like we don t give a f... Mentality and be like chilling , speaking at the house and singing for fun ....it went welll , event with technical issues that made us do some jokes ...ect ...

Ahhhh yes, the feeling that you don't belong on the stage with the "talent" that's also on that stage.....
 
I wonder if when BB King and Eric Clapton walk on stage together to do a show if they are both not thinking that very same thing....  "What the heck am I doing on stage with this guitar god?"...  wanna bet that doesn't cross their minds?
 
Would you turn down an opportunity to play on stage with your guitar hero no matter how amazing the guy or gal was?  Would you turn down a chance to jam on stage in front of people with Clapton, or Santana?  I know I wouldn't turn it down. I might make a fool of myself but damn.... I'd have a ball doing it. Then again, I might just play well enough and with no mistakes and knock it out of the park as the saying goes.   Either way, it would be a blast.
 
I was recently in a contest for the opportunity to play on stage with Vince Gill.... one of the hottest country pickers alive.... I didn't place into the top 5 so that isn't happening. However, had I placed, I would have gone to the finals and had a ball playing with a guy who has forgotten more about playing a guitar than I will ever likely know. It would have been fun.  So far, they have not posted the ranking below the top 5..... so I have no idea if I'm #6 (almost made it) or if I'm 596 in the list.
 
So, if you were invited to play, it's because someone thought you were of sufficient talent to be able to hold up your part of the gig.... so go, have fun and play from your heart and don't worry what the others are doing.

Searching the web, I can't find whether propanool is prescription or over-the-counter purchasable. If prescription, I do not believe my doctor would prescribe a drug just because of my stage fright. I think he would say deal with it in some natural means, although personally I would prefer a little help in the beginning. But would have to be careful to not become over attached to it.