Idk what to do and it’s stressing me out!

I have a condition called lupus (You might of heard of it Selena Gomez & Nick Cannon also have it but if you don’t know what it is search it up for better understanding of what a Chronic autoimmune disease is 🧐) and I have to take A LOT of medications 🤢. By taking these meds I have to take it with food. Let me just tell you that I’m not a big eater never have been, but when I take these meds I feel like I didn’t eat at all. I’m 17 turning 18 in May♊️. I’ve been diagnosed with lupus when I was 9 👧🏽 so by the years I’ve gained weight📈 lost weight📉. I have loads of stretch marks all of over my body and dark little spots on my thighs that remove with any creams (I’m really insecure about that I don’t wear shorts in public because of it, I’m thinking of getting a thigh tat to cover it), my boobs grew and shrunk (in 5th grade I was a D cup now I’m in 12th grade wearing a B cup), the meds cut my height everyone in my family is 5’9” to 6 foot while I’m the shortest 5’3 my nurse keeps saying I won’t grow anymore 😐 in my family I’m the only one with a condition everyone’s healthy and slim (Models should I say 😅 my grandma has high blood pressure but that’s all). Ik it sounds like I have a problem with my body but I don’t! I feel beautiful in whatever shape I am because if you want to look beautiful just make an effort right? I just want advice on what I should eat or do to keep my weight stabilized. I don’t want to go through a boob job or tummy tuck (if you go on IG or Snapchat you’ll see Dr. Cat Begovic she’s so AMAZING on what she does but it’s too much for me to think about going through that). My sister and I signed to go to the gym she’s fit and all but just wanted to get some touches and me on the other hand wanted to be on a stable weight number and gain muscle on my arms and legs but there’s a problem with my lupus it effects my kidneys so I can’t take protein shakes only organic things and I also have too much protein in my kidneys 🤦🏽‍♀️. Ughhh all this is just stressing ya girl out for no reason I just need some advice or help. O