All right. The first thing I'm going to advise you to do - or rather not do - is constantly putting yourself down so much. Humility may be a virtue, but constantly telling yourself that you can't do something is likely to become a self-fulfilling prophecy. Secondly, what you're describing doesn't sound like stupidity. It sounds like you're neuro-atypical, specifically mildly autistic. While that can make socialization - and by extension networking - considerably harder, the good news is that there's a plethora of effective strategies that can help drastically with that. I suggest you head over to one of the Autism communities and ask them for assistance with introducing you to them, and maybe help with finding the ones that'll work most effectively for you. I'm sure they'll be more than happy to help.

Finally, perhaps you can try to consciously veer away from focusing on the things in your life you feel you cannot currently do. Instead, try redirecting your focus to what you can do. It doesn't matter whether it's something big or something small. Even the smallest victory is still a victory, and every one of those is something you can use to build confidence which in turn can be leveraged to achieve more.

You'd probably benefit from talking to a therapist. They'd be able to work with you closely about your job search anxieties, your negative feelings about your intellect, and your challenges finding friends.