Welcome to NT!
I have only had spasms similar to yours twice. Once in my foot/ankle where the foot was stuck in 1 position and the other in my hip/hamstring where my leg wouldn't straighten/bend-stuck at a 45 degree angle. Most of the time they vary from feeling a "pull" to a charley horse type spasm.
I don't take anything for spasms. Most things just knock me out. However, when my leg got stuck I broke down and tried the Valium and aside from sleeping all day and night on 1/2 Valium it really did work.
I do hope you start feeling better soon and can find something that gives you relief. Check in with us when you can and let us know how you are doing.
BTW - I have not returned to work. The ADA would be a great place to start research accommodation options that are available to you should you be able to return to work.