Here is a solution for you. Firstly isolate your muscles during an exercise. Most likely your form is not correct (you may not even now it) . Secondly. Do not increase the weight. Theis is the problem aswell. Increase your reps. Minimum 15 reps per set. Learn to do 21s for biceps. It's very effective. Another piece of advice is train your triceps and your biceps will grow.
most people won't understand this