How do you recover from a break up when you were the one to end it?

I was in love with my bf - I thought he was the one but he treated me very badly and I decided to make the difficult decision to go on a break/end it to make him realize what he was doing wrong. Instead he behaved worse - tried to make me jealous in every way possible. Add a bunch of models from tinder. When I am not adding anyone or trying to hurt his feelings in any way (or flash it in his face if I ever see someone new). I just feel very hurt that when he was with me - after his 10 year relationship with his ex - we kept it hidden for a while to not hurt her feelings. But with me after 3 years - he is even capable of hitting on the girls I work with..I should I cope and move forward. How should I take it day by day seeing as it was he hardest decision I had to make