It’s BEEN 14 YEARS, IM READY TO LEAVE.

I’m in desperate need of some advice....I’ve been with my SO since high school. junior year at that...i was 16. I’m now 30 years. We started out as best friends and it somehow morphed into this relationship. We never spoke about it or anything we just started staying together when i got back from college bc he offered when i got back in town and was in need of a place to stay....and somehow we were dating. we’ve been living together ever since. Over the years it’s been a little rocky. But I’m starting to resent a lot of things. We aren’t married or anything no children, just 2 precious dogs. He doesn’t even seem interested in getting married...but he’s all i know. I almost feel obligated to stay bc of our families and friends and the things we have “established” but I’m honestly not happy. . I don’t feel like an individual bc I’m always associated with him. I never got things done after school bc he always wanted to do things together and would get upset if i got my own place or anything.. . I do love him, but I’m not that 16 year old anymore. I feel like I’ve outgrown this and i need to break away to be happy and find myself but idk how to do it without “hurting” him or with less drama. We have so much together and our pups and stuff like that...some days when I’m close to telling him, i think about how messy it could get and i get anxious and depressed. I don’t want to hurt him but i also don’t want to be unhappy for another 14 years. It’s costing me a lot of things bc most days my head is in a weird space and i just shut down and clam up. Any advice?