Dont-
I was where you were 6 months ago. I think that most of the folk here were too. We have all tested ourselves, had panic attacks, etc. I had a back and neck injury that started mine. I was testing myself with pushups making things worse wiht numbness and weakness which then fuled the "oh crap I have ALS and am going to die" panic. My neuro diagnosed anxiety and myofascial pain along with the sprains. That *beep* me off; "how dare he say I have anxiety, I am twitching!". Bottom line, ALS is a horrid NMD that should not be wished on one's worst enemy. However, it is also easy to spot and once you understand it and can work past the fear and think rationally about it, it is easier to calm down. Stories of slow onset, of people misdiagnosed, etc make an impression becuase you are scared. It is called the primacy effect; the tendency to remember the thing that grabbed your attention. How about the 600+ other people here who have been twiching for 20 years in some cases and no ALS? That is less reassuring if you are terrified than the idea of "but I read about one person who was misdiagnosed..." Primacy effect.
I have a friend, a guy I respect greatly, who has ALS and is almost to the point of needing a wheel chair. Watching the progression of the disease helped fuel my anxiety. However, he has never felt any of his twitching, has felt little pain and never felt an increase in weakness. Limbs just stopped working. No going back.
For me, understanding that the sensory events I was experiencing, the global twitcing I had, the muscle pain, the affective changes (crabby as hell to my wife and kids), the amount of time I was surfing the web looking at fasciculation, etc. all was fueling the fire. I finally went to yet another doctor (I am sticking with this one) who did indeed reiterate that I had anxiety, that I had had several neuro evals by a respected neuro, that there was no clinical weakness and that I was making things worse by perseverating and ruminating on my symptoms.
I was resistant to medication because I thougt it was a sign of weakness, was a character flaw for me. I finally got what they had all been saying. That I did not have ALS. That something was wrong, yes because I had benign fasciculations as the neuro said; but I was making things worse. I talked about my med concerns. Doc gave me a trial script for Ativan (.5 mg) PRN. I have taken it maybe 15 times in 3 months because I am still thinking I can deal with this without full meds. But bottom line is this. As I was able to calm myself, the anxiety faded (still have flareups), the fascics and pain get less, and that reinforces things. I have the luxury of having a background in mental health that helps me to do this for me. Talk to others. Talk to counselors if you are open to it. What I am saying is that anxiety, once surfaced, makes it all worse; it gets to our worst fears and starts to control us if unchecked.
If you can get the breaks somehow, use it to reinforce yourself. If it was ALS there would be no breaks. No good days. No going back. Just a downhill slide.
Like others here, I am angry at myself for wasting as many days as I have worrying about this. My daughters first christmas was marked by my worrying. Her first thanksgiving. My son's first school program. That is what helped me to put things in perspective.
Look around here. Read the stories of others. See what you have in common with them, with us. Listen to the docs. Do what you need to do to get your anxiety undercontrol before it takes you to really bad places; worse than where you are. This place has been a Godsend for me and for others. Use it. Good luck. Sorry for the length of this reply.