boyfriend leaving...

My boyfriend and I have been together for a year, we have a very strong bond. However, he wants to go to move to the states for school for 4 years in September and we live in Canada currently. I told him I support him, but I also don’t want to do a long distance relationship. I don’t want us to break up but I’ll also be heartbroken if he leaves....I want him to do what he wants so he won’t resent me in the future but this is also hard on me. What do I do or how do I go about this