Do you find this happens during the winter/fall seasons? You sound like something is going on in your head. (No offence, I 'm bipolar and I often felt as you do, only when I was depressed. I was more depressive than manic.) Do you ever get really really big boosts of energy, become talkative, excited, agitated easily, overly aggressive, fell extreamly anxious like you should be some where else?
I'm going to suggest you talk to a Doctor, or counseler. I know you may not like them, niether did I, but I know better now. They are tools that you use to get info for what "maybe" going on. They may help you out and make you feel a lot better. But you do have to give it time, and go through trial and errors. Better to fight for a chance at being at peace than always suffering eh? I did that for 10years before I finnaly worked hard enough on it to get better. You may not even need meds.
But that's just a suggestion.
Violin is hard to play, I like that kind of stuff, but I am trying to learn guitar. I call it my Guitfiddle. Haha.