I'm a single mom (23) and my boyfriend (26) is beginning to behave unpredictably.

My boyfriend and I have been together for nearly a year, and he has been a really great partner overall. However, every few months, I discover instances of online infidelity, concerning messages about me, or other unsettling behaviors. He also exhibits strong narcissistic traits and recently got extremely drunk at bars, even threatening me over the phone. Whenever we seem to be in a good place—about three months of what feels like a healthy relationship—he inevitably sabotages it through lies, getting involved with an OnlyFans account, or yelling at me while I’m pleading with him to calm down. His anger escalates to such an extent that he turns bright red, and it looks like he might burst with rage. Last night, after he got blackout drunk, we had several phone calls over six hours while he was out with a friend. I was in tears, begging him to settle down, but he laughed at my distress, physically threatened me, and emotionally abused me. My son calls him "dada," and he means the world to me. I can't understand why he would treat our family this way. While he provides for us, I’m close to finishing my degree and have no savings. I live far from my family and friends, at least three hours away. I'm scared. I love him, but my son’s well-being is my top priority. I’m at a loss as to what to do. How can I either fix this relationship or safely get out of it?