Relationship struggles

I've been in a relationship for 15 years and I feel confused. I know all relationships have their ups and downs but i recently learnt that my partner doesn't stand up for me and ever since I got off the bc pills, I've completely lost attraction for him and also have been struggling to connect emotionally. The sex and money is great but he's not great at understanding emotions and this makes it hard for me to connect to him and I find myself unhappy most of the time in the relationship. I then started to find myself being attracted to a friend that I only meet occasionally with in a group of friends.

Now in the past we both had a slight crush on one another and I've known him longer than my partner but we never dated one another and always saw him as a friend. Once I got on the bc pills, I completely lost attraction to him but once I got off of the pills, I started to find him attractive again. I enjoy hanging out with him but would never cheat and I can feel this is happening as well as I know all of the flaws and the good and the bad of my partner but I don't know much about this friend. i also can't go back on the pills again due to health reasons and do not want to use any hormonal ones as I did not like how it made me feel when I was on them. Our relationship is great on paper and I'm proud of his accomplishments and everyone is telling me to stay with him or that I'll regret it if I leave him and date anyone else.

I wanted to hear stories of anyone else who has been in this situation before?