good for you, if you already have someone who you know will treat you better, do what's better. i've been with my alcoholic/drug addict bf for four years, and beleive me although it can get better, it gets worst. you're sons deserve a father that can be there for them...you'll do only good for you and ur sons if you decide to leave. be strong, although it's hard, you'll get through it. it hasn't been easy for me but i've broken away two months ago and my life is so much nicer and clamer without all that insanity. do what's best for you.
hugs