hey all im new here so please tell me if im doing anything wrong

and please bare with me its a long story, ill keep it as simple as possible!
my girlfriend and i have just past the "honey moon" stage of our relationship if you will, and since then i always feel like she is going to break up with me
i get worried if she doesnt reply to my calls or txts thinking she doesnt care or doesnt want to talk to me, and sometimes i feel like she doesnt want to touch me or have sex with me anymore. i always have in the back of my head, what is she up to, is she cheating on me, does she still love me, is she going to leave me.
then i began to think maybe it could have something to do with thing that happened with my mother. When i was younger i was very close to my mother and she was the only female i truly trusted and i knew would never lie to me or leave me. her and my father started having problems and i said to her "promise you wont leave me or dad" and she promised she wouldnt, but she did.. she cheated on my dad and lied to me
i was wondering if maybe this could have something to do with the way im feeling, the woman that i loved and trusted most in my life lied to me and left me, so now im scared that my girlfriend is going to do it to me?
feedback would be greatly appricated!