I'm drifting apart from school friends before university... advice?

I finished my victory lap the other day (I did a half year rather than a year), and I now have almost no friends. As I basically took a gap year, a lot of my friends have moved on and gone onto university or college, and have moved to other cities. As a result, I don't see them often and they're too busy to talk, hanging with new friends. I 100% understand - I'm going to University six hours away from my home city in the fall, and I'm excited to hopefully make some great new friends there too.

The issue is that my friends still here, in my home city, and I have been drifting apart over the past little while, and we've basically stopped hanging out or even talking now. My best (female) friend of 13 years and I barely talk, and when we do, it's very brief and surface. We used to talk during class, but now without school we don't bother. It's the same with all my other friends in that friend group. Thing is, I understand that before/during university you lose a lot of friends but then eventually gain new ones (if all goes well), but I still have months and months to go! I don't want to spend all this term and summer alone. I like my friends, and I love their company. But then sometimes, specifically with my best friend, I just have this overwhelming feeling of... it's over. We've kind of outgrown each other, and my whole friend group are doing apprenticeships or community college, and getting married/into serious relationships. Meanwhile I'm single, moving to a big city and studying journalism, and even doing a planned exchange to the UK. Both are great life paths, but they're obviously very different. We don't have much in common anymore, and we don't have that much to talk about.

I'm just looking for advice on how I should handle this situation. Do I try really hard to repair the friendships, and keep those friends for occasional parties and events, but end up spending a lot of time alone? Or do I try to reconnect online with at-university friends, make new friends at jobs (trying to find one), and try to connect with acquaintances from my home city that otherwise might not become friendships? Basically... give up or keep trying? It's still so many months until I move. And I do love my friends :(