Has anyone here resigned themselves to a life of spinsterhood?

My relationship just leaves me so exhausted sometimes. I don't know if it's him, or me, or both, or neither, but it doesn't really matter. I'm 28 already, and so I doubt I could find another guy who loved me who I could love back. My boyfriend is great in so many ways that it's just like... if I don't want to spend my life with him, who else would I want to spend it with?

I am an extrovert, so I fear a life alone. But at the same time, I could probably build a decent social life in my world of glorious solitude, and perhaps that would make it easier.

I didn't post in /r/TwoXChromosomes or /r/relationships because I don't want "you go girl!" or "you don't need no man!" sorts of advice. I think that there's a great many loses that come from giving up on the relationship company of men, even down to simple things like having someone to help put together Ikea furniture, or drive during road trips, or do the home networking, and it's important to consider that. But at the same time, I think I'm too much of a misanthrope to ever truly love someone.