Sounds like many a relationship Oh_Henry, only difference is that you met this girl at an MP. There are many a gold digger hanging out in bars who are up to the same stuff. But be glad that you still have both your kidneys. [ An urban legend but WTF you get my point I think ] This is not a flame but sort of a balance to the overwhelming support, I guess most wince at this like they would if they saw you get kicked in the balls, and rightfully so.
Reminds me of a line in There's Something about Mary:
HEALY: "The bottom line is, I'm not going to use my philanthropy as some form of currency...especially after what I did. I lied to this poor girl. Lied. man. She deserved better."
SULLY : "Hey, love will make you do fucked-up things."
Guys do this kinda shit all the time too. I guess we have all done it to some degree or another (dumped someone, crushed their heart).
You sound like you've got a good head on your shoulders, and you have learned a lot about yourself. Just remember that love is a chemical response that nature has wired us up for and like any good drug it can fuck us up like a bad case of night time monkey agonies.