Most importantly, be angry at her as a person, not because of gender. Guys do shitty things to guys, too. Yes, being “shot down” by a woman is it’s own special pain. But the only way to never feel it is to never ask or forbid her from saying “no.” The first is a sad but legit behavior. But if you’re in the mix, you’re gonna get turned down. Be careful in your approaches and measured in your responses. It’s not rocket science.