Don't expect tablets to be a magic overnighter,they take time and you may have to try different doses of different tablets.I gave up on them tbh.People don't actually realise what goes on sometimes.The worst thing for me is when people say "whats up with you you miserable c*nt" and half the time I feel reasonably ok.
I am now 37 and have suffered with depression since I was about 13.I do have an hereditary illness that I was diagnosed with at 21,there is no cure and depression is a part of the illness.I know all to well about the shutting off/away side.It is hard to deal with,the doctors nowaday are far better than they used to be and they will send you for counseling and sometimes it can work.Good luck and try to keep your head up.
Try to do thigs you love doing as much as possible,it helps me.If I used to spend a couple of hours on my motocross bike or in my cosworth and I am a different person . . . untill the next day.