I hate being the one to point out that the increase in sex is not a good sign. As awesome as you might think. He is currently focusing his attention elsewhere with other girls, regardless of what he does with them, but still gets to have you for sex when he gets home. A common term would be to "have his cake and eat it too."
Think about it. He ended it with you and yet he still gets to have sex with you? What about that makes sense to you?
You are a person that has dropped everything for this guy and bent over backwards to be with him and he just lost his interest unfortunately. You shouldn't have to drop what you are doing and change your life around for somebody, no matter how much you thought he was "the one". Because in reality there is more than one "one" out there for us, and I just feel like you are clawing and fighting for this investment you put in this person.
A relationship should never be put over yourself. You should never have to rearrange and revolve your life around somebody, no matter how much you care about them. Because this situation can happen where even with your 100 percent, it still might not be enough. And what's left after it's broken?
I know we are taught if something really matters to us, we should fight for it with everything we got. But anything you do right now is just going to push him far away. Giving into his demands of sex won't get you anywhere. Letting him stick around won't either. You have to kick him out of the house and focus on getting your life back on track without him. Because I don't think he really cares about the effort you have put in for him when he is fooling around with other girls. You need some time apart to get your priorities in line, and he needs time apart without you in his life to realize how much he cares (or doesn't care). That's the only remedy for the situation.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.