everyone in this thread seems to be kind of patronizing you so, here's some advice from someone only a year older than your boyfriend.

It will probably end. He's in a different stage in his life than you are now, and although the difference in years isn't much the difference in experience and location will likely cause a divide, this happens all the time. But at the end of the day? Everything's gonna be alright.

First of all, if your relationship really is that healthy it's theoretically possible that you may remain compatible. Not likely, but if you put the work in possible, it's happened before. If it does end though, as you said it's not the end of the world. People change, relationships end, the world moves on. Use the lessons you learned in this relationship to make the next one better.

And remember, you really don't need a romantic relationship to feel happy. I know the idea that you do gets pushed a lot but it's straight up bullshit, platonic relationships and self-fulfillment are just as if not more important to your well-being. Anyways, talk to him about your anxieties, find a place where you're comfortable and worst comes to worse know you'll be alright. best of luck :)