Just stop thinking of all the happy moments and train yourself to think of all the bad moments with her/him enough to make you not even want to think about them no more, and also just keep yourself busy and take some time away from dating till your ready, don't jump right into dating someone else ether as your head is not clear enough, have fun with your friends and just do what you enjoy without your ex to get used to her/him not being around, remember they are an ex for a reason and the things they did should not be forgotten because then it will help you learn from them and figure out ways to better your future relationships, but for now just chill and have some breathing time.
Put yourself out there. Go have fun being single with your friends and hanging out with the people who you have fun with. And then when you meet a MUCH better girl along the way (because it usually happens when you least expect it) you'll almost forget the last girl exists. Sitting around at home is the last thing I'd suggest, because I know when I'm bored my mind likes to wander. You need to keep yourself busy.
everyone heals in different ways, personally I would focus on something else and not think about dating for a while, pick up a new hobby...
I have no clue my cheating ex and I broke up 2 years ago and I'm still not over it. And I got with other guys. Sometimes it just takes time.
Hit her where it hurts date a girl you know she hates! Date as much as you can right now that's how you will get over her!