That really doesn't sound bad, as far as it goes. You have a decent balance between your instruments.
One thing I learned quickly with this stuff is that the more you know, the more you know you don't know.
Listen to songs in the songs forum, and when people offer technical critiques, listen for what they are talking about.
I've learned a ton here.
Read, watch videos, absorb as much as you can. Like most of us, I am still learning. You will, too.
Don't sweat kontakt. Yes, it's nice, but you can get respectable sound from even modest synths like TTS1.
When you are playing your MIDI keyboard, don't think keyboard. Get involved with the virtual instrument you are playing. Your mindset has almost as much to do with getting good sound from MIDI soft synths as the samples do.
I realize that is somewhat abstract, but it works. By way of example, check out Khyber Pass9 at my Soundclick page. This is all virtual instruments played with my keyboard. You can do it.
Read, read, read, thrash your keyboard, try stuff. Don't be afraid to trash a project. You're not paying for studio time. Good luck, and above all, keep it fun.