LME, I think it's very understandable to have these feelings at times. My arthritis is become increasingly debilitating and I cannot do the things I used to do (and I'm 29). For one, it has made me not feel myself because I can't go to the gym anymore, I can't play with my nephews, etc. But, I also don't feel like going anywhere and I don't feel attractive because I have lost all of the muscle I worked so hard to gain at the gym and have gained fat in it's place. I'm still thin for my height, but my body shape has changed and I can't wear some of the clothes I used to wear. I feel like it would cause problems with my husband except that he has back problems and he hurts too badly to do stuff most of the time as well. We are like two really old people except that we're both 29.
I know it's hard, but you should take pride in the fact that you are already more than half way to your weight goal and you are actually improving from when you first got sick. Keep up hope that this pattern continues. And there is nothing wrong with thinking of yourself as a sick person...you do need to remember to take it easier on your body than you did before you got sick. But, think of things that you couldn't do before when you were sicker that you can do now and you will see that you have come a long way. Hopefully that will continue.
If you feel like you need extra help, see a therapist, psychiatrist, support group, etc. I take anti-depressants/anti-anxiety meds and they do help me. I still feel negative at times and I know that I shouldn't, but the meds help and then I remind myself that it's been worse (and could be worse again), so I should be thankful for what I can do right now.