Jealousy is the grave of affection.

I really torment myself :( I don't understand why I am so upset. I felt so jealous today, so mad even. So here is the story.
Back in December when I was in Colorado Duke and I attended our company's' Christmas party. Afterwards we decided to go out. We met up with people from work at Lavish, a nearby bar. I was having a good time and then I turned and this girl, dark hair, too tight of a dress and somewhat pretty was sitting on my boyfriends lap. At the time it wasn't very important to me. I could see that Duke was not comfortable, I knew she was intoxicated and I felt confident that my love was madly in love with me. I let him know I wasn't happy but I thought I moved on. I wish it had stayed that way. I don't know why but the more I thought about it the more I became upset. I was so mad I wanted to leave the bar. I am still mad about it almost two months later. Probably because this woman sees Duke and texts him. How often, I do not know. I have not asked and I feel I shouldn't. I'm really upset though and I do not understand why. That night we went back to the hotel, I was mad at him. I really don't like the bitch! Can't try to make it sound nice anymore, it was disrespectful, I don't understand why he didn't ask her to get off him and I felt hurt. There I said it! I hate the Bitch.
This doesn't feel like me. I know Duke loves me so why am I so insecure. I just hope I don't ruin our relationship, feels like I'm trying to sabotage this.