What Causes Weakness In Legs And Arms And Internal Shaking?

Hi doctor. I have been feeling weak in my legs and arms mostly. This past weeks a few mornings i woke up with an internal type of shaking that went away shortly after i had been awake. I also suffer from acid reflux pretty frequently but i dont know if that has anything to do with these symptoms. I feel nervous at times and anxious and i am pretty worried about my symptoms. Also sometimes when i sweat while playing a sport i get a little cold. i dont know if that isn ormal or not. I am a 21 year old male. Please help