motivation???

So in the last year my depressed and stress has hit me hard. Unfortunately I don't know how to get out of this "not wanting to do anything" I had 2 jobs when I was 18/19 now I'm 20 and I sit inside all day. I don't wanna do anything at all. I also gain about 50/60 pounds in this last year and I want to loose it so bad!! I know what I have to do.. but I can't. Any advice? How can I get myself up and ready to do stuff? Please and thank you!!!