Body image, weight gain, self esteem

I've always been fairly slim and remained the same weight throughout most of my life. I've had issues with body image the whole time, but gotten better at enjoying food. Now I'm about to turn 26 and this past year has been a real game changer. I was temporarily on the progesterone only pill, but came off again because it wasnt helping me with my bad cramps. On it I gained weight, which I thought would come off again, but it hasn't. I think I was a size EU 40 about two years ago and today I'm struggling with EU 44 and constantly feeling bloated, so nothing really feels comfortable to wear. (I'm talking jeans here, which I used to love wearing, although leggings are still winners!) Every day I'm having a hissy fit when I try to get dressed. I dont feel comfortable in anything I own and I feel disgusted by myself in the mirror. I'm seeing cellulite on the front of my thighs and stomach, when I used to only have it on my butt and backs of my thighs. I'm freaking out over how much my body is changing. I dont think my habits have changed that much. I'm still a sugar addict and if anything, I've gone to the gym more this past year than ever before.

How do I get over this? I've never had such bad self image as I do today.