Yep this is a problem. My first "girlfriend" in college was a huge problem. I thought we were more serious than she did, and I fell pretty hard for her. She did something (I think got drunk and kissed one of our friends) and I just couldn't handle it. I basically shut down and withdrew for a long time. Her and our friends basically cut me out of everything because I was being very antisocial. I ended up failing a few classes, it was bad.
The next year I met my wife online, dropped out of college, and moved across the country, and so I guess I've only had 1 bad experience. I of course fell hard for my wife but it worked out. 