Quite frankly, I don't know how guys deal with being at rush and trying to impress guys AND girls at the same time.
I think that you are perhaps being more cautious than you would normally be because of the bad experience you had. That's perfectly natural. Just remind yourself these are not the same guys - they sound like much nicer guys to me - and that you are not the same person, you've grown up. The fact that you took responsibility for your end of the deal speaks a lot to that.
Just try to take each experience as it's happening and don't get hung up on what was or what will be, and you'll most likely loosen up and have a better time.