One thing that is very easy to try in your situation is magnesium supplementation. Most people in our society are lacking in this macro mineral. Magnesium is resposible for many important bodily functions and one of the most important is the relaxing of muscles. If I was you I would get some magnesium citrate (liquid) and have anywhere form 1000mg to 2000mg every day for a couple weeks and see if your situation improves.
Many "diseases" (especially where muscles are involved) are helped by getting proper doses of magnesium. Good luck.