I have nerve damage in my feet from diabetes. Mostly numbness but some pain too. If I can keep blood sugar under control will my feet get better?

It is possible. Some diabetic nerve damage is reversible. Watch you sugar intake, and have your vitamin b levels checked and supplemented as necessary.
Unlikely. Unfortunately, oftentimes it doesn't reverse or go away even if you start controling your diabetes (might even transiently worsen for a brief amount of time when you first tighten your blood sugar control). However, even if its bad now, it can get worse so it is still definitely worthwhile focusing on improving your diabetes control.
May or may not. It all depends on the reversibility of the damage. If the damage is not permanent, it may get better, but if it is, it won't, but it is still worth trying to get it under control, so it won't get worse.