Is it normal this bothers me almost everyday?

I have these two friends named.. i'll just say lilo and stitch. Lilo and stitch are best friends, and yes they are both girls. They were always there for me when i needed relationship advice and everything else. Stitch had an on and off relationship with a guy, i'll call him tommy. Tommy happens to be my ex boyfriends best friend. When Stitch was having problems with Tommy she always came to me to maybe have my ex talk to tommy. Long story short.. A long time ago Tommy and I used to talk but no one ever knew except his best friend (my ex) .. he was a player and he was talking to stitch the whole time he was talking to me. My ex and I broke up. A couple months later tommy and Stitch broke up and years later Tommy and I became real great friends. Of course Stitch still had feelings for him.. and like most girls we feel we have "ownership" on the guys we had loved before to where we get jealous when they hang out with other girls and what not. Stitch and I were great friends too but she never knew I had a close relationship with Tommy. One day I needed a ride to another town to pick up a package and so i had asked Tommy. Though Tommy and Stitch weren't together i had asked Stitch for her permission to have tommy take mt and she said yes.
One day I wasn't able to go home and of course i had called tommy to take me but i called him from a friends phone who took the bus home. My phone was dead so i couldn't tell Stitch that tommy was taking me home. He went to go pick up pizza for home so thats where we went before he had dropped me off. He got out to get the pizza and before he did Lilo, Stitch's best friend saw him. So as a best friend lilo told stitch but she didn't know that the girl was me. Long story short, Tommy told her the girl was me so Sticth called me and told me she was very disappointed in me. I understand that i was wrong and that she feels betrayed considering the fact that she always came to me for advice on him. I had apologize but she never talked to me again.. but I guess now her and Tommy are working things out. Of course Lilo is mad at me as well. How can i be mature about this? i know i shouldn't care about what people say about me but even though what we did was very innocent i can't help but feel that they are calling me a hoe behind my back.. I already apologize but i got no answer. now, i know better than to beg for forgiveness. I have a very guilty conscience and everyday this bothers me.