How do you know the relationship has run its course?

Hi! I’m sure this has been posted a bunch of times, but I wanted to see what some of you thought about my situation.

I am in my early twenties (23F) and have been dating my boyfriend (22M) for 2.5 years. We are currently long distance, as he just finished college in Virginia (where we met) and I’m living in NYC. I plan on spending my 20s moving around to try different wildlife jobs, while I know he wants to settle down eventually in a big city. Our relationship is great, we’re both happy and steady and there aren’t any huge conflicts. He is such a wonderful partner and has done so much for me, too much to thank. However, I’m not really sure how I feel being in a long term relationship, as I’m not sure if I even want to be married. The thought of being strapped down in a committed relationship for my entire 20s seems miserable.

I hated being single in college, but I think I’ve changed so much since then and would love it now (of course I’m only thinking about the good parts of it). There is truly nothing wrong with this relationship, I just think it may have run its course. But it’s impossible to imagine a life without him and it would be so sad to end it. I can’t tell if the sadness would be from it being the wrong decision or just being because a long term relationship with someone I love is ending. I just am starting to feel like I’m losing myself in this relationship? The reality is I want to try dating more people and try new experiences, especially if I want to move around. But how do I explain that to someone? Is that enough to break up? How did you know it was time to end, even if it was a good relationship?

Any advice is wonderful, but please keep it kind; this is a super hard thing for me to navigate. Our lives are extremely connected and it would be so hard to let go of it all. Also we are currently long distance and his birthday is next week. Our next trip to see each other isn’t until late August (which ofc I already bought a non-refundable plane ticket for) so I think it would have to be over the phone. I don’t have the time off or money to travel just for a break up, and neither does he.

TL;DR – how do I know when a relationship has run its course even if it’s healthy?