I really need advice - please help

So, I'm 18 years old and I've lived with my Great grand parents since I was 3 months.. they've raised me till now and I love them to death, I consider them my mom and my dad. I have a great relationship with my dad but my moms always been really tough on me. She's basically always said I'd grow up and end up miserable like my birth mother. My whole life has been me trying to be better than my birth mother. I'm still attending school, I don't have any kids, I'm looking for a job. I'm trying to do something with my life.. about 7 months ago I met my current boyfriend. We started off as friends and then best friends and after like 6 months he asked me out. He is very supportive and unlike any other man I've been with.. recently things at home have been horrible and I have the option to move out now since I'm 18 and I could move in with my boyfriend. He works a lot, he's no low life and if I lived with him I'd have a more supportive environment, he'd help me find a job and I could still attend school but when I told my mother about it she just says I'm gonna fail miserably and if I fall and can't pick myself up she won't help me.. if I needed her she would just let me suffer. She's very emotionally manipulative and I'm starting to doubt my decisions... what do you think..? Anything helps