Hello:
I also have a problem with having a personality that is too overtly "plain"
(actually, I am a very interesting person as the sum of all parts, but I present as a bit stone-faced and unexciting, especially on a first-impression) It takes me some time to warm up to anybody before I start to open up and the full range of my interests comes out. (I usually blow the 1st impression though and don't get to the next step)
My problem is also that my personality and interests are very obscure things that no one is likely to identify with or relate to........ This make it difficult in relationships. Moving forward, my ideal girl and I will share life goals and dreams and our romance will blossom out of shared desires for life.
But I am like you to where my personality type is obscure and no one can really relate to me. Its a tough road I know.
I don't fall at all into a major subset of male-personality types...... therefore I never run across any girl who will fancy me and make moves towards me since I am most likely to be never what she thinks she might be looking for on a broad base. I think most girls generally look for some subset of male like "partyboy," "entrepreneur" etc.
I can't even say in general what I might be. I have 3 or 4 very specific interests I work hard at, but no real indicator of a great general personality. I'm not even really a "nerd," or a "geek"
I think you, as the OP, have yet to totally define what your personality is though. You are still fluid enough I think you have lots of potential to perhaps pick up on some "general interest" or sense of being that perhaps many girls will be able to relate to.
I think as well as polishing a few specific interests, you should think about more general things.