Yeah the topical creams are really only effective for mild strains, or tired muscles. Spasms? No they won't really work.

I have really tight rhomboid muscles, upper back right next to the scapula. This is where my stress accumulates. It can bother me at night as either a dull ache, or move up and I can really feel it in my neck. I've tried a lot of stuff - new pillow, topical analgesics, Tylenol, NSAIDs - I get some relief, not much. But after a really good, deep tissue massage by a great masseuse, I did get some relief.

There is a branch of medicine called Functional Medicine - this is sometimes called sports medicine - and there are MDs specializing in this. I found one to help with mysterious and sporadic cramps in my hamstrings. Turned out it was lumbar degeneration - and a host of other ailments - exacerbated by very tight low back muscles. So it was like flashes of sciatic pain, never lasting for longer than a few seconds. So I've added low back stretches and have gotten a little relief.

If valium is helping you then go with it. Just please be careful with these benzo drugs as they are very addictive.