It is the eustachian tube that is affecting your balance, not the deviated septum. I hope the surgery is better now. I had deviated septum surgery on my left side in the early 1970s and it didn't help. I went through the entire procedure and the two weeks recovery afterwards and I did not get any benefit but I'm sure they're more skilled at it now. I wouldn't put my hopes of getting better balance on the deviated septum surgery. I always had good balance when I was younger regardless of the deviated septum. I took modern dance classes which requires quite a bit of balance with all the turns, Etc. My left side did not feel heavy though so I'm not sure what is causing that problem. Sending hugs.