Salam. Eat protein from halal fish (fins and scales are a sign of halal fish)
Some Shias allow eating shrimp or prawns
Tinned fish like sardines, salmon or tuna are easy because they don't need to be cooked
Other protein items if your stomach can tolerate them:
beans, garbanzo or chickpeas, hummus, lentils, yellow split peas, etc.
almonds, cashews, Brazil nuts, pecans, walnuts, peanuts, almond butter, peanut butter, etc.
eggs
plain yogurt with no gelatin and no added sugar if possible
cheese if it doesn't make you feel bad
tofu or tempeh if you are familiar with those
protein drinks that contain less than 5 grams of sugar if your doctor wants you to limit sugar