Heartbroken still :0(?

Sorry im sitting here and i actually feel like im crazy. my partner left after 10 yrs together and 2 small kiddies its been 6 months now so quite long. thing is it hasnt been complete break as we been seeing each other and talked bout getting bk. But now things have turned horrible partly beacuse he has been playing mind games and i feel like total mug as its only me who keeps getting hurt. I do love him and wud love my family bk but it wont work now too much has been said and done BUT i cant let him go maybe its the rejection i just dont know. He has told me recently he seeing new girl and all his friends on stupif facebook r girls and one particular girl who works in his local pub has become his new bf.....i hate her. I am full of jealousy and i hate it so so much. I have good friends and good social life and busy with kids but i always end up thinking of him and my stomach churns just at the thought of him with this girl....i shud be the one cuddling him, sleeping with him, me and kids shud be with him being a family. I know i sound pathetic but trust me i hate myself for feeling these things cause he has treated me so so bad and i should walk away so wot is stopping me??????????????? I think once the jealousy fades i'll be so much betta. I wish i could turn bk time :( just hoping this pain fades as he is loving his single life and being with these girls where i feel sick at the thought of dating again. He has so moved onand saids he dont love me now which kills. Will this jealous pain fade? Has ne one else been in similar position? I feel crazy as i wanna know wot he doing and who he with and wot the girls look like and im never usually like this when we was together i was really chilled so now him with these girls and rubbing it in my face hurts so so much. sorry for rambling on but needed to clear my head a bot thanx xx