Codependency in a relationship

I discovered today that I'm in a codependent relationship as the caregiver and I overly sacrifice myself for their happiness.

I cant stop repeating the last time I saw them when I was apologising to them for having to go to the point I began to cry as they did nothing except take away something that made us both happy which was if I leave to go home they will not visit me in 2 weeks time.

That idea I had been introduced to that day and was so excited about because I always travel to them.

That is a 3-4 hour travel on public transport