Why am I twitching so much?

[JChristensen]

Back in December I started having a lot of twitching, particularly in my left arm. It had me completely freaked out and I also had a strange feeling in my left bicep. I went to the dr and he referred me to a neurologist for an EMG/NCV. The test came back normal. They ran blood tests. The only thing they can see is that my thyroid levels have been dropping, but are still within normal range. Last month my TSH was .52 with a lab range of .5-5 being normal. My T3 and T4 are also right in the middle of being normal. I've never been tested for thyroid antibodies though or checked for thyroiditis. All these drs keep just sending me home with a prescription for anxiety, but they don't realize that the anxiety started AFTER I was twitching. I've had a twitch in my left middle finger for like a week now but this also happened before with my bicep and it went away after a few days. I also have TMJ type symptoms now. I'm seeing a dr in 2 weeks that's doing a full vitamin and hormone panel. I'm really scared of what this could be and I'm tired of going to SO many appointments and never getting an answer. I've googled and googled and seen everything from scary stuff like ALS/MND, to simpler things like vitamin D deficiency, thyroid issues, BFS, etc. I just want to know whether there's a serious problem or not. I really don't know what to do anymore. :( Any help is greatly appreciated.