Sorry it didn't work out. Keep the other chapters in mind for future rushes. Every fraternity looks for different things; you just have to be yourself. If the brothers like you for who you are, that is all that matters. I wouldn't have done anything differently except for ONE thing....
When the brothers stopped inviting you to events, that should have been a clear sign that this fraternity was no longer an option for you. They aren't obligated to call you and tell you that you're not going on in the process. Instead, they're relying on you having the social grace to understand that no call about the next event/event that night means you've been cut. I don't think leaving that one party 2 hours after it started was a big deal-- your ride wanted to go home. Why would he drive 20 minutes to get home if the only intent was to drop 2 rushees off and then go back to the party? If you were going to be cut, it would be after that evening's events, not during them. I think you are reading too much into that. You were there for 2 hours-- that is a good amount of time to spend mixing and meeting new people. If the guys decided then and there you weren't moving on in the process, they would just stop talking to you at the event so that you would get the hint. They wouldn't get someone to take you home-- that's far too much effort on their part.
If you hadn't been invited to invite-only events, you really put the brothers in an uncomfortable situation by showing up uninvited or calling them to find out where the event was being held. If they wanted you to know, you would have been invited. You put them in a very awkward position and probably killed any future chances with that group because you decided, "They haven't cut me. They just forgot to call me and tell me where the rush event was." Not likely this would happen so many nights in a row.
You feel like you were a good fit for the fraternity. The members didn't. Based on your actions-- being a little aggressive find out where events were-- events you hadn't been invited to after several events with the brothers -- I think you just didn't know when they were just being polite and showing you the door. Without knowing you, I'd argue that you probably seemed like a nice and enthusiastic guy at first and then came on way too strong once they got to know you better. It is great to show interest. It's another to beat someone over the head with your interest. It's kind of like dating. You have to be cool, show interest and let the other party lead a little bit, too.
Give the other chapters a chance and good luck! Keep us posted.
Small request- can you break up your paragraphs with some spacing? It's a little hard to read and some people might be turned off from reading your full story and offering suggestions or feedback. Thanks so much!! 
