Overthinking and losing sleep over this thing that happened years ago

My first 2 weeks of college i had a roommate. She was friends with some girls down the hall. From the start they kind of excluded me. They would go to parties and not invite me and say there wasnt enough room in the uber. They would all hang out in one of the other girls room and not ask me and i would hear them laughing and having a good time and it really hurt.

The day after we moved in my roommate asked me to drive to the liquor store and pick up her friend so we could buy wine. When we got back we all took a picture together and I stood on the end, and then they uploaded it to instagram and snapchat and cropped me out of it.

Those 2 weeks were the worst experience of my life. Now, i always ask myself whats wrong with me, why am I so horrible that all of them felt the need to do that. Im just so sad and upset about it still even though it happened years ago it still keeps me up at night.  I feel sick and horrible thinking about it 3 years later and i feel like something is wrong with me.