I'm losing my best friend and it's killing me 💔

We used to be so tight. We met where we used to work. We turned into friends with benefits. We were so close. Even after I left where we worked we still kept in touch. I love him so much. But now he owns his own businesses and doesn't have time for me anymore and it hurts like hell. Idk what to do about this, if there's anything I can do. I hate losing people but I guess that's the way it goes sometimes. I just wish I could do something about it. I used to tell him everything but we hardly ever talk anymore, and I definitely never see him. Any advice would be appreciated.