Hi LMD,
I hope you don't mind that I abbreviated your name. If you prefer the whole thing, just correct me, I promise I'll get it right the next time!
I understand what you are saying. I had a long conversation about this with a friend of mine because I felt the same way. I used to enjoy reading and going out with friends but anything outside of laying in the bed or on the couch all day felt like work. So even though reading may make me happy or keep my mind off of the things in my life that make me unhappy, it's not a permanent "fix" so to speak.
Unfortunately I don't have an answer for you, but if you aren't seeking treatment then it may be an option to look into. Before I became depressed, I enjoyed helping people and making a difference in their lives. Right now I'm still struggling but I'm getting to a point that I may be able to do things like that again. I hope that you are able to find something soon. Good luck!
As a side note, I recognized your profile picture as the cover from "Catching Fire" from the Hunger Games. Is that because you like the movie/book, or is it just because you like the picture?