Am I making a mistake?

Next month I am moving 17 hours away to be with my significant other, we have been together since we are 15 and now are 24, I need to make this move to see if we work well living together and my sister has been telling me it is a stupid choice because she doesn’t like my boyfriend because since we have been together since teenagers, he hasn’t always treated me the best. My sister says I need to stay here and find someone here and that it is just a bad choice. I was excited for this life changing move but now am worried what if it is a bad choice like she says because I’m leaving my parents and sister and nieces and nephew. Any advice. By the way we also have spent multiple weeks in person together, I wasn’t clear on if we spent any time together & he treats me good now, just went we were teenagers it was rough.