Why dont i hate my dad?

Every thing he has done to me and my mum. im 13 im a girl and thay broke up when i was 6 . i see him almost ever friday and some times i get to stay with him untill late sunday . thay still some times has arguments and my dad is a lier as well ... he also moved into relation ships to fast he moved in with them like strate away ! and kinda forgets about me and his gf will become all he cares about and like when thay brake up im all he cares about untill he find anuver girl friend ... and like he might promice me some thing and then i will never get it or ita be like 2 years and then ill get it ( no joke ) all theys things and yet i still love my dad sooo much .. my mum dusent want me seeying him she says ita be better for me not to have him in my life ! but if i say i wana see him she will drive me down to him or he will drive half way and i will have time with him my mum only trys to keep me happy and keep me in contact with my dad but still after every thing he has done to me n my mum (lies) and so on i still love him sooo much like on saturday im going ice skating with him ! but like on saturday he might change his mind and we wont go all theys tipe of things or his gf will piss him off and he will get angry and we wont go .. why do i still love him . YES I KNOW MY SPELLING IS CRAP ! but please just answer the question x