Help with confidence?

I’m 5’4” and I am about 210 lbs. Sometimes I think I look good until I see my reflection or someone takes a picture of me etc. I have cellulite pretty bad and summer time is always very depressing for me. I feel disgusting the entire time and I won’t wear shorts or tank tops, I’d rather sweat my ass off. But tomorrow I’m going to a cook out with some family and friends. There’s going to be other women there and I’m so nervous about being in a swimsuit. My husband of course says I look amazing but I just can’t. I think I look absolutely disgusting and I can’t handle it. I just want to sit and cry. I know I’m going to be self conscious the entire time and it’s to the point that I don’t even want to go. I just want to feel good about myself for once and have fun. I’m never having fun because I self conscious and I’m constantly thinking about the way I look. Idk what to do.