I don't recall the earlier versions.
Good song. Excellent job on the vocals. Hitting and holding that high note was perfect.
The nits to me: in my opinion.
Guitar: lose the chorus unless you're going for a Def Lepard sound.
Bass: I had a hard time figuring out if there was one in the song.
Drums: sound like slapping cardbord boxes. Not even close to sounding right IMHO
You said you're using Dim Pro for the bass. I'm not sure, although I do have Dim Pro, what the samples or patches sound like. I found that Cakewalk Sound Center has what I consider to be a really nice full sounding bass in a sample called Ricko Bass. It's my go-to bass when I'm needing a midi bass part.
What are you using for drums? Most drum synths and samplers I have seen and heard have really nice sounding drums straight out of the box. I, like others, then apply some EQ and compression to tweeze the sound a bit. It's possible to start with a really nice drum sound and with EQ and compression totally destroy the dynamics and the tone if you're not careful. It's also possible to take a good sounding drum and make it better with the same compression and EQ.
Roll off most everything below 40hz if you have low end noise. If you don't....then don't roll it off.
A bass doesn't need (IMHO) ..."it's own space" in a mix. I think it needs to be a part of the mix and it needs to work closely with the drums, especially the kick.
When the mix is not going as planned.....the only choice you have to salvage it and get it right is to go back to square one. If you keep trying to save a mix that is so far off course, there's a good chance you won't get it back on course with more tweeks.
From every channel and track and bus, remove the plugs, the EQ, the compression, and start from square one. Raw tracks. Now, if you use Ozone.... use a rock preset or something similar and drop it into the master. It will put some EQ in place to give a decent starting point for the overall mix. Also throw in a very light reverb.... 10% or so..... nothing really noticeable. I start every mix in a similar way. Set up the overall sound.
Start by muting everything except the drums.... drop a single cake or other track EQ in and push the highs and the lows a bit by a few db simply to accentuate them. Let the kick be felt.
Now add the bass. Solo as needed and if you need..... some EQ... just a tad, but... the bass sound should be working with the kick drum and together they should be a single cohesive sound unit. Done right, you should be able to add vocals and call it done. But we're still going to add the other instruments. Simply making a point as to how well they should be fitting together at this point.
The rest of the mix at this point is simply a matter of putting the icing on the proverbial cake. The bass and drums are the foundation upon which you build that house. Without that foundation, it's like the guy in that song that built his house upon the sand......
I called it putting the icing on the cake but we all know it's not that simple..... lots of hard work goes into that part but you seem to have a decent grasp on the vox guitar parts. The low end is where I hear most of the problems..... mainly from a lack thereof as other here have mentioned as well.
I said to go back to square one, and I mean that.....however...... you could probably salvage the low end by soloing the drums and then the bass and following the procedures I mentioned for the specific tracks in question.
Remove the chorus from the guitar and solo it and listen carefully to the tone.....I'm with Beagle, I thought it wasn't a steel string as well. Work the EQ to bring out the natural sound of the wood and strings. Make it sound like an acoustic guitar. Chorus on a guitar has to be done carefully to avoid sounding dated, and more so on acoustic. I'd personally delete the chorus and simply record the acoustic rhythm guitar on 2 tracks, a unique recording each time, trying to be as close as possible to the exact same performance....and pan them fairly hard opposite each other to give width to the mix without the chorus effect.
You have a good song.... just a few problems in the mix as I see it.
OK that's my advice.... I'm shutting up now....