i feel like i’m crumbling

hi. this feels weird to say but i (20f) just broke up with my bf. he was my first boyfriend, my first love. but our relationship had grown really toxic. even though i know it was the healthy thing for me to do i can't stop crying. i love him so much still. i don't know what to do, i feel like im going to have a mental breakdown over this. any and all replies highly appreciated.