Albumin Deficiency and Lupus: Seeking Advice

Does anyone know about protein deficiency? Specifically albumin deficiency. I have SLE and hashimotos and recently have been experiencing a lot of symptoms, more joint issues like tmj, more fatigue attacks, drops in blood oxygen levels making me dizzy and most importantly swollen feet with pitting edema, the doctors were worried about my kidneys and ran tests but decided I’m severely albumin deficient and have been for a long time. I’m not malnourished though so I don’t understand why, I have been having utis recently thanks to my lupus and inflammation and I’m very vit d deficient so have just been prescribed 40,000 units of vit d weekly so perhaps this is why? I’ve not heard of any young people experiencing hypoalbuminemia without liver or kidney or heart failure and I have no clue what to do about it I already eat as best as I can and lupus patients aren’t even meant to have much protein anyway since it’s immune boosting so I don’t know what I can do, the symptoms are awful. Does anyone know anything or have any advice?