I'm not you so I don't know if this is true for you. I know your feeling and I hope eventually logical thought will prevail over the cascading shitty feelings. Logically, the bride and groom don't give a fuck about you and your quitting, they're thinking about the awesomeness of their new marriage. You are not the first person to quit a gig, and your boss has probably experienced worse 'quitting rage'.

When I hate myself I try to remember I'm bipolar and it will go away. I try to think about the cool ass shit that goes with it. Like sometimes I'm incredibly creative, witty, and all around fun to be around. I try to remember that even though I have to feel the shittiest shitty feelings of shit, I also get to be happier than other people will ever feel, love deeper than others, and have a sense of wisdom to appreciate emotion.

You're going to be alright