Most Helpful Guy
Just leave the situation if it's bad. Only worry about you, don't worry about whether he feels bad about it afterwards or not. Only reason to do that is to lead him to come back to you, and it sounds like that's not what's best for you. So it doesn't matter if he's learned anything from it if you make a clean break. If you're trying to teach him a lesson to try to "fix" him and rekindle the relationship, that's a different approach, and it would be playing games to leave with the intent of him regretting it and chasing after you. Decide if you're done or not, then go ahead and be done, or not. If you're not done, let him know your issues with his behavior and tell him you're almost done. But you have to decisively pick your approach, you can't walk in the middle of the road.
Most Helpful Girl
Go to the gym, work out.
Become 10 x hotter then he will ever be.
Date a really rich hot guy.
Try to make yourslef look your best. (Work on your hair, ect)
Walk past him a lot and look really happy with your new rich hot boyfriend