Hi everyone, apologies for the long post but this has been bothering me for a long time.

I've noticed shaking / a slight tremor for over a year now when doing certain activities or doing fine movements. For example, when holding my phone up in bed or putting my arms up above my head when standing and controlling them down to my sides again, my shoulder muscles shake slightly. Another example is when standing on my tippy toes and bringing my heel back to the ground in a controlled manner, it's not smooth, instead, it's sort of shaky through my lower legs? Does anyone else get these? It's always during a rather slow controlled movement. I'm so hyperfocused on this now I don't know what's normal and what isn't anymore.

I’ve noticed since then that my upper arms get tired very easily, and when I do the slightest exertion with my muscles, they shake as if they are strained (like the day after a workout) and I'm jittery quite often. 

I have severe health anxiety and worry it's neurological but my doctors don't think it's anything and all of my bloods came back normal. Private neurologists near me have a 4-6 month waiting time, and I'm kinda terrified because I worry that my body is degenerating. I still have the strength to do everything I used to e.g. opening things and lifting things, I just shake sometimes like my muscles are easily fatigued.  

As background info, I'm 21M and used to be very fit but mainly stopped exercising 4-5 years ago when I took up tech studies.  Could this just be due to lack of exercise + stress? Have you experienced similar?

Thanks in advance for any insights.