My left arm biceps started to twitch, no solution?

I am 21, male, Do not know where to start so i am just gonna write, first notices it 7 months ago when my left arm biceps started to twitch, initially i thought it would stop it did not it persisted to twitch 24 hours a day, when i am awake and when i sleep so i went to the doctor and she said it happens and that i should consume more magnesium and i took it every day but twitching continued, went to the other doctor month after she sent me to emergency to take many tests and go to many doctors, nobody knew why is this happening, so i ordered another exemination in my city capital and they did that nerve test (witch i already did in my city) results were the same that it is not nerves, so since i told them i did’nt feel any weakness in that arm so they told me they don’t know what it is and that i should just live with it, the thing is its been like this for 7 months now and i feel twitches in my legs and even forehead, i am just looking what is wrong with me? i refuse to accept it is nothing
i did blood test, urine test, nerves test, MRI(upper and lower) but machine is a bit old,