I swear, everytime I try to lose weight, something physical happens.

For years I battled with endometriosis, and finally had a hysterectomy (and both ovaries removed) last fall (at 26). I don't think my hormones are right (had them switched once already) I am HUNGRY all the time. I had my thyroid removed when I was 15, so that's an obstacle too. I have Lupus w/ moderate to severe joint pain/fatigue. Now I've been diagnosed with this awful baldder condition-Interstitial Cystitis- back in December. My bladder hurts when I take a short walk, and I can have no artificial sweeteners, limited water, and limited fruits. It's just sooooo frustrating. I feel sometimes like I'm making excuses, then I feel like I might be depressed, but some days it's just so hard to get out of bed- especially with two kids.
Any advice on how to handle this with weight loss? Tips? TIA