Daughter Keeping me Alive

I am so down and I can't get over it. I have PPD and it's been really hard coping with body changes since I used to be in the gym 6 days a week. I was dealing with this amongst other thing when I discovered my husband developed a porn habit. Of course when I'm at my lowest... he doesn't look anymore but now we fight constantly and he makes me hate myself as a person. I think about killing myself all the time but I love my daughter too much and I know she needs me.
I don't know what to do. I can't sleep and I'm so unhappy. I turned 26 3 weeks ago so I lost coverage and I can't afford health insurance so I can't get help for my depression. I'm just stuck feeling this way.