Seeking guidance

Assalamualaikum, I'm a young Muslim who messed up by getting into a forbidden relationship, and now it's dragging down my iman, my studies, and my connection with my parents. I feel crushed and lost. I want to cut it off and sincerely repent to Allah. I've tried ending it before, but this person guilt-trips me into staying. Should I just block them completely without saying anything? Need some advice, please.