Hi and welcome,
It's understandable to have some levels of anxiety with not knowing what is causing these types of issues but from what you have mentioned, it is highly unlikely to be MS and whilst i don't know as much about ALS, it honestly doesn't sound like what happens with something like ALS either.
With neurological conditions like RRMS, symptoms are primarily caused by the brain and or spinal cord lesions, and because of the way damage from these lesions work, if this was a 'first MS attack' you wouldn't be experiencing any symptom all over or in all peripheral limbs (arms and legs).
Neurologically caused muscle weakness is measurable, it's not a perception of weakness per say but actual weakness eg a leg will feel like it's got extra weight attached to it, which makes that leg feel weaker and heavier the more you try to use it and that understandably affects the way you walk. Basically the same thing if the weakness is in an arm, the arm will be harder to use in everyday tasks like brushing your hair etc
The bulk of this has really only been happening over the last 3 weeks, it was originally numbness in you 'right' baby toe and then a few weeks later your 'right' arm felt strange before it changed later that same day to twitching all over etc
You've mentioned anxiety and fear so i'll bring up mental health.....It's 'possible' your anxiety and fears of what might be wrong, is now causing you to experience things like the all over twitching and the perception of all peripheral limb weakness, i'm not saying it is, just that anxiety is a possible explanation for all over muscle twitching etc. and to be clear, mental health is not the only explanation but if you are experiencing high levels of anxiety and fear it's something you should also consider being a contributing factor to everything that's happening to you....
Try and take a step back if you can, there are many alternative medical explanations that are nothing like MS or ALS and if you focus on any specific causation at this stage you'll likely be worrying about something that you don't actually have......breath, you'll have a better idea of what might be going on once you've seen the neurologist.
Hope that helps..........JJ
ps oh just a thought but it might help your anxiety if you avoid doing things like googling, googling can actually make people feel even more anxious sometimes..