I agree with Eric - you must eliminate things like Lyme and other neuro related diseases first. See a neuro first!!
But my bet is that your twitching is coming from stress and anxiety - especially with being diagnosed with Anxiety Disorder. Could this be any more apparrent? ALS should be the furthest thing from your mind right now... if your read the BFS IN A NUTSHELL section before you posted...
... you would know that twitching is a secondary symptom in isolated areas (usually legs first) AFTER measureable weakness in your muscles. AND it does not get better the next day. Twitching isn't even that noticebal with ALS victims - it's NOT a primary symptom. PLUS - only 30,000 in the enitre USA has ALS... 30,000 out of 290 million. And 90-95% of them get it after age 50!!! You have nothing to worry about as far as ALS goes.
What you need to do is address your anxiety disorder. There are ways to address this issue, both with meds and without. My advise is to start without meds. Things like excercise, meditation and seeing a therapist could be helpful. Wiping out all the uneccessary "clutter" and "noise" in your life can help. If not, there are still a myriad of ways to address your anxiety.
Also, focus on your life, your friends, on doing stuff.. get and and play.., have some fun!! Trust me... the more you focus on your symtoms, the more they will reveal themselves. Read the posts on this board... people who worry cause more worry and see more symptoms.
Best of luck. Let us know how you progress.