You treated girl 1 really badly for a very shallow reason. "I'm dumping you right before Valentine's Day for another girl." You should feel like an ass because you were one. The fact that you don't see how hurt and pissed she'll be and think you can go right back and say "my bad" shows you haven't matured or thought about how your actions have consequences for others and yourself. Accept the consequences that you blew it and learn from that so you don't do it again.