It sounds like you need to eat, quite simply, but this doesn't mean go eat junk. From your lack of concentration and hairloss and coldness, you sound malnourished, so eat fruit, lots of fruit, and veggies, and lean protein if you're not vegetarian. You won't get fat if you're not eating grains/fats/cheese but fruits & veggies will feed your brain, then you can decide where to go from there. Or if you need, go to a therapist to help you get started. Good luck, and you can always come here for support.