Cheated on my boyfriend

So I just recently celebrated my 21st birthday, and as most people do, I made a bad decision. I have been with my boyfriend for 4 years now, but for the last couple of months, I haven’t been happy. He never comes home (we live together in my parents basement) and never helps me with anything. I get stressed out with school and work, and constantly cleaning up after him. Well the night of my 21st, he left bc he was mad that my work managers were there and I was talking to them (they are all 25 so pretty close to my age) and decided to leave because “I wouldn’t talk to him” so he did. I was extremely mad and upset bc I’ve never had just one night to myself. So I went to another bar and drank a lot, and when we was leaving, I didn’t have anywhere to stay, so one of my managers, the only single one actually, called me 5 times, asking me to stay with him, so I did. And I had sex with him twice this night. I have no idea what to do, I can’t even look at my boyfriend knowing what I did. I haven’t been eating for like a week and I’m just stuck, any advice would be appreciated !!