I hear you. I’m a big nerd. I work with cisco networking equipment all day. I watch Sunday night cartoons and I play video games at 28.
I think I see some of what your problem is. A certain level of interest doesn’t come from the subject matter, but how YOU present it. Anything can be interesting (or boring) depending on who’s doing the talking. Case in point, you probably had some awesome teachers and some terrible ones that made/broke the class.
Don’t be so scared of being alone. That’s your first problem is you’re validating who you are and your self worth based on who’s around you. That’s a lesson only you can learn on your own. Figure out what you like about yourself and add more too it. Get excited about you and you’ll be exciting to someone. (You’ll be a muse; an inspiration for others. It’s very catchy.)
And if they’re that boring and shallow to where they don’t find you interesting, screw them. 
You’ll be ok. Just take baby steps and make adjustments.