It's horrible to feel like this, I know exactly how you feel!!
Do you have any goals that your working towards, sometimes setting goals helps me to feel a bit more like I have something to work towards and aim for! although sometimes I can end up being disappointed in myself if I can reach a goal - so I guess not always a good thing!
I understand what you mean about
not knowing who you are aswell, sometimes I feel that I have lost my sense of self! Talking with my counsellor has really really helped with this!
"The Optimist sees the rose and not its thorns; the pessimist stares at the thorns, oblivious of the rose."