The hollowness is from not being useful to someone. I went through your EXACT same thing. 17, graduated, moved in with my sweetheart (and her mother…), got a place of our own to rent at 23, married at 26, divorced at 36, alone entirely when my parents died 38, and 41. Now 43, the best advice I can give you is to forgive yourself, go outside, reconnect with the things that bring YOU joy (for me, that was getting back into flying) and volunteer and give back to the community around you.

You’ll find that hollowness was self-inflicted.

A dog is a great companion as well.