Help!! How Do I get out of this deep dark depression?

I need help. For the past couple of years I've been in a bad depression. I have two beautiful kids who I'm so proud of. I want to be happy and be able to enjoy life with them. They make me smile, but this depression, anxiety, feeling so low and horrible affects what we all do. I never want to leave the house. I dread going outside to take them to play. So they usually play inside the house, unless someone else takes them outside. And it's summer I just want to be able to enjoy things with them. I can't though. I hate how I feel since I've gained baby weight. I want to get out and walk, but I'm so depressed I don't want people to see or talk to me. I want to get some sun, but Im scared everybody is going to make fun of how I look. I dread holidays, which is horrible because I'm usually soo excited for them, but the past few have been bad, somehow they always get ruined by people. I hate feeling like this. But, there have been some bad things happen to me in the past and it's hard to pull myself out of this when I have no help. I don't have medical insurance or I would try to get on some medicine. How do I stop caring what other people think?? Please help me out if you know of anyway I can get out of this. Thanks.