Thin arms and legs. I do any tests?

I am 5'7. Basically My bmi is fine. My weight is 70kg now(after eating healthy food after quarantine at home) I had a gastric attack last year which i ignored for a month, inturn which turned me thin(65kgs~). So, i marked i had thin arms and legs. I'm suffering from tinnitus, which restricts me from lifting heavy weights as it flares up my tinnitus. So, the problem now m facing is, my stomach's increasing, even chest has grown, but my arms are legs are still thin. I thought its genetic but my mom dad doesn't have any such problems. Is it possible I'm having celiac disease? I usually get acid reflux now a days not much but i get it Should I do any tests? I feel/think there's malabsorption and malnutrition happening. Please help me. I want to look healthy atleast.