I went through a phase of feeling nothing. It had to do with the extreme pain I had in my head from an aggravation in my brain, which was operated on 3 times and radiated for 30 days. I became emotionally cold, because the pain overwhelmed anything I felt. I couldn't even cry, and feeling anything just became harder and harder. I got through it, though.
I found something to live for, I found people to talk to, and I get into therapy. Therapy didn't help much, but I started a full-time job working nights (11P-7:30A) and that helped get me out of the house and doing something other than mope around feeling nothing. I started eating healthier and that seemed to boost my mood as well. I tried to take a holistic approach, and it worked. I started taking a multivitamin, vitamin C, and L-theanine, which is a stress-reducing supplement, and they all seemed to also help. I began getting more sun. Sun has healing properties, but just don't overdo it (i.e. get burned).
You have to try everything that might help in order to truly know what helps. Start with improving your health, exercise, and try meditating as well. Get some sun and try to breathe deeply. Trust me, the oxygen certainly makes things feel better. Best of luck and I hope these suggestions were useful.