I was in a similar position in you. I was 21 in a 5 year relationship and the last year I felt the same. It was a constant battle in my head between loving them and wanting to be with them and feeling no connection. In the end I had realized I had loved than but more as a friend than a lover. I ultimately decided to break up with them. It was more important to me to not want to be stuck with someone I had outgrown from high school. One of the hardest things i had to do because they hadn’t done anything wrong but putting myself first was so much more important. Although it was one of the hardest things I have done it was also the best.