<human>: Can you summarize the given text in a few sentences?

Throughout most of my youth, I was very anti-social, rarely conversating with anyone of the opposite sex. In High school, I met a girl that I'll call M in class. Before I continue, let me just say that there was never anything going on that exceed the boundaries of friendship. The relation started slow but eventually we started to text/snapchat/talk every day. This went on all semester. We would even occasionally go out to play badminton. After first semester, things died out and we started talking less and less. At this point I don't even talk to her anymore unless its about something for class. I think its both our faults (I'm starting to find our conversations a little boring too).  I don't know what went wrong and I've never had this experience before. Any thoughts as to what could have gone wrong? Any advice as to what I can do differently to keep a friendship going? Thanks for reading!
<bot>: A friendship I had with someone of the opposite sex slowly died. Don't know what happened, but would like some advice/tips to not make the same mistakes in the future.