Your twitching, when it happens, how it feels, none of it has anything to do with danger to you or your health.
Fasciculations are not part of symptoms doctors use to diagnose ALS. Doctors make note of them, but they are not part of the criteria used to diagnose it.
ALS is a disease that causes weakness and atrophy.
I can tell you from personal experience, that I have weakness and quite visible atrophy where I've never ever noticed a fasciculation, some places I had twitching, and also have atrophy and weakness. So it does not follow that where one sees twitching , that something malignant is going on. In a person that has ALS, its part of the disease, but it doesn't mean that if you twitch you've got that disease, anymore than a person who has a bad headache has a brain tumor.
Do the very best thing you can do for your health, and stop watching for twitches, testing yourself, and reading about possible symptoms on the internet. You've been twitching a long time. You would have clinical weakness now if it was anything within the category of the MND's.
It does not seem like what people say to you when you ask for reassurance actually calm you. If your doctors can tell you you don't have ALS, and the members here have responded as well, then this is not what you need to feel less afraid. You need to change your focus to something else.
If you're unable to put this aside, if you research back through previous threads, there is one titled"first symptoms?" started by me. Within that thread, BethU added a link to a very helpful BFS support and information site. Perhaps reading and getting involved there would help you.
I understand that they are upsetting, no one is saying that they aren't. You just aren't helping yourself by allowing fear of something like this consume you.
take care, and the best of luck to you in getting through this.