I wish you speedy recovery, but I would like to also add that stance and the way you stand and position your head has alot to do with most of the back & neck issues, there are some ways that help you prevent issues if you stand in a more natural way.
Some people like to straighten their left leg and bending their right leg (Depending on how they hold the cue obviously) to make a stance that looks like a snooker stance, which for pool in my opinion isn't good for your back, the best way in my opinion is to bend both knees slightly and have the back to be more straighter than how it look when you stand in a snooker stance position (Straight legged) which I don't recommend.
If you watch Earl strickland or efren in his early, they bend both knees, Earl bends them more so, and this helps your back severly specially if you are tall guy.
For the neck issue, I also recommend having your neck look straightening within your back, I don't know how to explain it well, I have to show you in person, but ill try to explain and give examples.
If you go down on a ball, try to look at the ball with the top edge of your eyes, so you want to bend your chin to the inside of your body, so that when you bend yourself, your head will still be straight as it was while you are standing, just look at jason shaw or SVB.
The wrong head position is when you tilt it upwards and start to see the balls straight to your face, if you see the snooker player Stephen Hendry or John Higgins, both of them use the bad head position, which is, they bend their backs, but the tilt their head up , so their face is straight toward the table, this will cause stress to the backside of your neck because its bending, which will cause problems in the future.
so to fix this just move your forehead more so down, don't pull it up when you go down on the ball.