I'm not talking about my looks, I mean the vibe that I give off.
Dude, seriously?
I tend to have what mental health experts call a "flat affect." But that's only when I'm around people who just want to talk about random b.s. I realize that my emotional state changes when I surround myself around intellectuals. Particularly people who are both smart and funny.
If your close friends are telling you that you take yourself too seriously, I'd listen to them and just try to relax. I've forced myself to have a more pleasant demeanor. I'm still not "open" to being around certain people and participating in certain things, but I've become more flexible. I don't know what your exact situation is, and I'm purposefully trying not to go into too much detail about my situation. I'm trying to be as vague as possible. As it relates to this thread, I think that once you've found that potential significant other your whole vibe could change.