No appetite

I've been prett ill since November. Exhausted, weird infections, swollen lymph nodes. I also found out in December that I have Celiac disease. I started eating gluten free in January, but my symptoms are getting worse. I tried an elimination diet to weed out some other food issues and figured out that I can't eat nightshade veggies, any grains, and I'm lactose intolerant too In February my appetite totally disappeared, and the lymph nodes in my neck make swallowing difficult. I'm having a hard time putting away even 500 calories a day, and when I eat more I usually puke. I certainly can't exercise, even walking around my campus at school is taxing. I also have two kids, so I was exhausted anyway. I've been to doctors, lots of them, no one knows what's up and they basically blow me off. I'm still seeing more, testing for lupus and lymphoma. So in the meantime what do I do? I wanted to lose weight, and I've lost a lot, 70lbs since January of last year. Now it has stalled out though. I don't believe in starvation mode, I've done research and from some threads on here many others don't believe it either. Why has my weight loss stalled, not that that's my main comcern? I'm basically suffering from anorexia at this point, even though I don't want to. Any tips for adding more calories? I can't do most protein powders because of the gluten and dairy issues. I need enough energy to exercise and function though. I'm having a hard time just getting out of bed, things like cleaning the house and playing with my kids have become impossible. Any thoughts or tips would be greatly appreciated! Thanks.