Triggers are funny little buggers. They come out of no where and slam into you like a Mack Truck.
In essence, they suck.
Will you ALWAYS feel this way about weddings. Probably not. But if it's not weddings it may be a song, or a TV show or a magazine article. The subconscious works in funny ways like that.
Just breathe and allow yourself to move through the trigger. You're human and your feelings are just that your feelings.
Hang in there and don't be so hard on yourself.