Advice on feeling lost after a sudden break up?

Exactly two months ago my boyfriend of a year and a half broke up with me literally out of nowhere. I’ve seen many posts of people complaining about a breakup coming out of nowhere, but this one truly did. He told me that for the past 5 months he’d been losing feelings and it got worse over the past weeks before the break up. We are still teenagers, so the amount of time we’d been together is pretty significant for our age. He was my long term friend before he confessed to me, he’d liked me for years beforehand. The moment he told me he’d lost interest I became so sick, since he hadn’t told me a thing and always claimed that « communication is key ». I’ve been a wreck ever since then, I thought I had been getting better, but the last couple of weeks my heart aches so bad. Our families had become close, we went on multiple vacations together, planned everything together. He didn’t tell me the reason he lost feelings because he also apparently didn’t know. I feel so lost, I can’t focus on anything, because i lost not only my boyfriend, but a long term friend, alongside many mutual friends. I feel so alone and knowing that he is doing well without me hurts so much. I have no idea what to do. I know a lot of adults take my feelings for granted since we’re still young, but i genuinely have no idea what to do. I feel like even after so much time had passed I am only getting worse. I have no motivation to do anything and feel numb all of the time. He told me that he had no problem remaining friends and i thought so too, but after seeing him in a photo a mutual friend had posted, I couldn’t stop crying. Please, if anyone knows how to deal with a similar situation, let me know.