Need Help losing weight and getting a healthy Life style

I am 22 and a mother to a wonderful 14 mo the old boy. my problem is when I got pregnant and all through my pregnancy I let myself go. I gained a ton of weight. i went from being 160 which was not completely healthy to being now 280. i am 5 feet 5 inches tall and I'm honestly in need of help. I really need to become healthy not only for myself but my husband and my son as well. I know my diet is one part of the puzzle and exercise is the other but I can not find a good fit for me. I have weekend knees and ankles also 14 mo this ago I had a C-section and the scar area is still rather painful when trying to do planks or push ups.