can you post a picture of your setup?
If there's very limited space (small table) then you can use russian style, which is putting the keyboard on your lap (google and youtube). It's not as weird as you might think and actually is pretty comfortable for playing, more than the regular setup, because that way the elbow has complete support and there's a lot of space for the mouse/mousepad.
What I personally do is using the regular setup (kb+mouse next each other) with a small keyboard (expensive) and a qck heavy (huge mousepad), with tape holding the mouse cord. I still use a crt on my gaming pc and it's on top of some books rofl. Elbows go into adjustable height arms of my chair.
Funny thing is russian style beats all what I described comfort-wise, it is more consistent (lan) and costs $0.