I feel really bad 😔 opinions ?

I started a new job a couple months ago and during the last few weeks, one of my coworkers has been flirting with me. He’s married and I have a bf. Well these last few days, his flirting has become more intense. My bf and I were having issues at the time that it started so I didn’t feel as guilty but recently my bf has been good to me because he said he wants to be a better bf, so I stopped wanting my coworker’s attention after that. Anyway, today my coworker offered to give me a ride home because I was stuck at work and hadn’t called my ride yet. Well the entire way he kinda held my hand. I kept telling him that I liked it but that it wasn’t right because I have a man and that I felt bad about it. Well when we got to my house, he kissed me before I got out of his car. I didn’t stop him and now I feel awful because I really do love my bf and I never thought I could do something like this 😔 I feel ashamed and don’t know whether or not to tell my bf or just pretend none of this ever happened and move on with my life and never do anything like this again . My coworker is leaving for another job next week and I just want to forget about him. I just can’t take this guilt anymore tho 😢 I’m such a horrible woman not only for doing this to my bf but his wife. I don’t even know what to do with myself