I don't want to generalize but at her age, she isn't 100 percent secure with herself, which contributes to her hangups about you having your old ex memorabilia. There isn't really much you can do about that unfortunately, and even if you did throw everything you had away to "prove" to her that you were committed, it still wouldn't guarentee the relationship or her security would increase. That kind of thing takes some time and comes with age. Everybody is different though, but if this relationship was on an even keel in terms of trust and respect, you probably wouldn't be in this situation at the moment.
It is a very typical thing to want to not let something go and to keep chasing after what you believe in and love. It's very romantic wouldn't you say. But as mentioned, it is just pushing her away. If she is trying to bury you, are you going to keep popping out of the ground again like it's Night Of The Living Dead? Don't make it any more of a nightmare than it is. And I'm not talking about how bad my analogy was.
You have to just let her be and if she finds somebody else, there isn't much you can do about it. Keep in mind that it's not very likely she will, but it's not your concern and shouldn't be something you should just be waiting for. Give her time and space and if she wants to talk to you she will. Don't miss out on any opportunities that you could be open to waiting around for somebody that is undecisive and throwing a tantrum in front of her parents about how "mean" and "bad" you are.
I know it's something that you can't really think about now, and I'm not telling you to go chase some strange tail. Just get out and have a good time and do what makes you happy. You might be a little out of the 4 nights a week party range and that's okay. You have your priorities in line, you might be able to find somebody that has theirs in as well. I'm just being presumptious but when I was 20 years old at college, partying was my number one priority too. She has alot to learn, alot of maturing to do, and who knows where you will be a couple years down the road if you don't run into each other or end up talking before then. Whether it works out or not, everything is going to be okay in the big picture.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.