<human>: I [F/24] was recently in a 2-month "relationship," if you will with a man [M/23] who seemed so committed. He expressed many times that he was serious about me. We were very emotionally (and obviously physically) intimate. I met his family and best friends. Then, seemingly out of nowhere I begin to feel distance from him. It's all but over now and I have NO IDEA WHAT HAPPENED.

I'm devastated, which sounds silly since we were only seeing each other for a short time, but I'm the kind of person who doesn't get attached easily or often, so when I do find someone I care for my mind is wholly invested.

I've talked to friends about this who have experienced something similar. What is really happening when a shift happens so quickly? Do you think there's a problem with our generation thinking others are disposable? How do you ever feel secure in a relationship knowing the other could flip the switch without any warning?

Give me the gist of the text in a nutshell
<bot>: Very close with a guy, he suddenly lost interest, confused about why/how and wondering how to ever feel secure in a relationship