Im fat and i hate it.

Im 5'1 normally weigh 130-140.

Had my daughter 6 months ago. I now weigh 204... i have horrible stretch marks. I feel very gross, my boyfriend (father of my child) and i have been together for 1 1/2. I hate myself, im not sexy, the only thing i can think about it how fat i am. How can i look at myself in a more positive way?