I’m cheating. I need advice!

Hello! Let me thank everyone for their opinions and thought before I get into the scenario. So I’m a little confused because I kind of got myself into a rut. I’ve been with my boyfriend for over 9 years we met in high school he really is my best friend. We’ve had our ups and down as any relationship does. He’s an angel but then he can be the devil. Weird to say it’s like we’re friends with benefits we don’t really hold hands, kiss, or do the regular couple thing. Since we’ve moved into his dads house everything has changed he’s verbally abusive, mentally and physically. I make excuses always saying it’s because of the stressful environment but then I remember there is no excuses for the actions that are I encountered. Yes he’s cheated on me physical and socially (online) I’ve dealt with it as I do with everything. I recently met a friend about a year ago, we started out as friends and of course feelings became involved I’ve never physically cheated but I have talked to this person in a confiding way and grew a deep bond. It’s getting confusing because I don’t know if I like this person in a lusty way because they show me everything I ever wanted but then I still have the bipolar bf who randomly wants to treat me right every time I want to leave. It’s like do I risk it and leave? Or do I stay with what I know ? I’m just so lost and confused idk how to handle the situation I’m so concerned about everyone else’s feelings but mine.