Losing weight to get pregnant !

My husband and I have been trying to conceive for over six months now. I have been off depo birth control-shot for more than a year and a half now but I was only on it for 9 months . I’ve gained a lot of weight quick when I was on the shot. I ’m tracking my fertile days through this app but no luck yet. I am overweight ... I understand that I need to loose at least 50lbs to get pregnant . I need help ... any recommendations & tips will be appreciated.