Well, it's normal. The strength of two hands is different. The pain in your right hand means that your right hand may not be able to accept such a great force. Now I can make a 50KG arm stick, fast, but not slow. I don't need to practice this number of times, as long as each one is standard, and multiple groups can do it. Practice slowly and stick to it for a while. Pain is normal. I went to the gym to practice these days. I just went on the first day and saw that the equipment was heavy. After practice, I tell you, it's very painful. I couldn't help it the next day. Therefore, the amount should be increased slowly, and it doesn't need too much intensity just after training.