How do you tell your mom you have a boyfriend??!!

I told my mom I had a boyfriend and she did not approve of it at all.  I'm 18 and I have things I want to achieve in life like getting my bachelors degree when I go uni, meeting my boyfriend who might end up going to a different uni again and having children with him and get married.  My mom have it rough in the past with my dad who had a wife before her.  My boyfriend is caring, he makes sure I get a bus to go home, he buys food for me to eat when I go out even if I say no or not really hungry and he's always looking out for me and tells me sweet dreams before I go sleep and good morning when I wake up.  My mom wants me to focus on my college degree, go university then help her with things but I need to live my life. She doesn't want me to get pregnant now (I understand) but I hardly get to go out and I feel dull because I have to study all the time and I don't remember things sometimes.  She thinks the ppl are trying to get at her, she thinks that if I go out with friends they gonna out poison in my food or carry me some where where there are other ppl waiting to rape me or something.  Some times I think she paranoid.  I can't stand it now longer and I don't want my only way out to be suicide.  I feel helpless.  I love my boyfriend.  You ever met that special friend that actually gets what you say?? That's him!!  My mom just don't understand that all men ain't the same.  He's 19 and working.  My mom thinks that all boyfriends have more than one girlfriends.  Not MINE that's how much I trust him.  Any advice??