Relationships are complicated....until they aren't.
You are interested in a person. This somehow leads to the two of you in a romantic relationship. You care for this person and the most significant aspect of your romantic relationship is that you want their life to be as amazing as it can possibly be.
Then, the things that make their life amazing change. You can’t be a part of that equation in the same way, as much as you both might want to fight it, your relationship must change.
Nothing about this changes how much you care about this person, or how deeply you still desire their life to be amazing.The only thing that changes is how you care for this person. Perhaps from a distance, perhaps without intimacy, perhaps only in phone calls. But there’s nothing complicated about this. You still want the best for this person, because they deserve it, and not being in a romantic relationship any longer doesn’t change any aspect of that.
Relationships will never stop changing, they will be different every morning when you wake up, and you have to, and want to, hold space for those changes. The thing that makes caring for a person so valuable is the ability to hold onto it through all of that. To continue to be the loving and generous person you were within the space of that relationship despite how it may have changed is what makes the relationship so valuable. That’s what you can’t ever let go of. There’s nothing complicated about this.