I'm thinking anxiety but my diet isn't very great
I have no idea to be honest, I think you should see a doctor for the breathing stopping. Weak hair is caused by many things. how's your diet ?
Most health problems come up in leaving middle age to senior age, but some young folks are unlucky and get the problems early. This includes sleep apnea, the form obstructive sleep apnea is physical and can something wrong in the breathing path that was "received" at birth, that is rarely the case.
To the point of the above, your symptoms sound more like obstructive sleep apnea, it can be aggrivated by being over weight, at any age... another reason to manage one's weight - here just giving what I know, not trying to diagnose you beyond suggesting you look into the subject obstructive sleep apnea. The other form is either mental of sub-mental (unconscious control of body functions), and it could, I suppose be aggravated by anxiety. I think anxiety is harder to manage than weight, both are a task we all have to deal with at some level.