Why have i wasted 10 years on this man?

well it all started 10 years ago i met aman who i thought was the man of my dreams i already had 3 kids from another relationship we fell in love well i did i fell pregnant had a miscarrige soon we tried for another baby i fell pregnant again we had a little boy we were so happy then things started to change he never turned up when he said when i rang he never answerd he started to hurt me but i still wouldnt let him go more years went on with us like this then one day i found out he had 1 other child the same age as ares we had together and that this other women was pregnant again i also found out i was pregnant as well but to top it all of i found out he had been sleeping with my best freind and she was also pregnant but no i still took him back even after all that why i really dont no still dont i think its cause i couldnt bare to loose him so we got back together we were ok my best mate who i still talk to didnt have the baby but the other women did she had a girl my partner didnt