I’m so uncomfortable with myself

I need help! I can’t lose my baby weight, she’s 20 months! I get so discouraged and put myself down and just give up. I want to lose 40-50 lbs. I just feel like I can’t I have always struggled with keeping weight off but I just feel like I am failing completely. I just got engaged and would absolutely love it if I can lose weight and be fit for my wedding. I just want to be happy with the way I look and I feel like it’s been forever since I could look in the mirror and smile. I just don’t know what to do