Breakup from boyfriend and his family

My long distance boyfriend and I broke up almost 4 months ago. I’ve really been struggling with it. We were together for almost 2 years. I thought I was going to marry him someday and I was close with his family. I’ve been trying to get him and his family out of my mind and my life but they always seem to work their way back in somehow. I got a text from his mom the other day after not hearing from her in almost 4 months. She said “hey, I hope you’re doing well. I miss you.” It completely threw off my day. I have so much guilt and regret. I just want things to go back to the way they were before.