<human>: Can you summarize the given text in a few sentences?

I know the title is weird, but I'm not sure how else to phrase it. This is the first time I'm really writing out what I've been feeling and thinking, so please excuse any grammar errors or rambling lines.

I'm a 21 year old female. I've been dating my boyfriend for six years. We've grown up together, and he's been my best friend since day 1. But I don't feel the same when I send time with him. I enjoy talking to him, but I don't feel like I need to see or be around him anymore. I feel like I enjoy the time I have by myself more than the time I have with him. We live separately, and now that I'm a young adult and have a better understanding of my own wants and desires, I've realized that I might enjoy being alone for a change. 

The thing is, I don't think his feelings have changed for me. And he really is a great guy, which is what has kept me from breaking things off with him. I feel like it'd be a mistake to let go of someone as kind and lovely as he is, but at the same time, I feel like staying with him would be unfair because I no longer feel the same way for him. I do love him. But I don't feel like I can be in a relationship anymore because I don't love being in a relationship with him. Does that make sense? I'm pretty sure it doesn't. It's a complicated thing I'm feeling. I'm not saying I want to leave him because I want to fuck a bunch of guys instead. I'm saying I would much enjoy being alone rather than being in a relationship with someone.

I guess what I'm asking is: do you think it'd be a mistake to leave someone who treats me well, just because I want to be alone?
<bot>: Been dating boyfriend for 6 years. He loves me, but I'm not sure if I want to be in a relationship anymore. I want to be alone for a change. Is it a mistake to leave him?