Penetration Vs Clit stimulation

Sooo I've realized whenever I tried to give myself clitoral stimulation at the same time as im receiving penetration, it hurts and doesn't feel too great. But if im lying down and not doing any penetration, and I rub myself on my clit, then it doesn't hurt. It only hurts when something is inside me. Why is that?? Am I just that sensitive ¿😔 I feel like me being super sensitive prevents me from feeling and enjoying A LOT of things with my partner down there.