How do you find kindred spirits?

I have a lot of friends, but I feel very alone lately. Even with my best friend or my boyfriend, I probably only feel comfortable discussing about 50% of what’s on my mind with them. It feels like I have this vast reservoir of thought that I can’t share with anyone because they wouldn’t “get” it- what I’m thinking is too touchy-feely, artsy, weird, or emotional to talk about. I lost a close friend a while back who understood almost everything, but we were so different that we had trouble getting along. Ugh. What is this that I’m feeling? I feel so creative and pent-up, but really isolated, and I just want to talk to someone who’s on the same wavelength. Has anyone else ever felt this way?