What I don't do (much) is question other people when they show an interest in me, particularly when I'm interested in them. I stay sensitive to the chemistry and allow myself to enjoy interacting and spending time with them without worrying about why. If you quit focusing so much on why they're interested in you and whether or not you're good enough for them, you will enjoy their company more and build stronger connections.
So yeah, don't sell yourself short, allow yourself to become invested in the relationships you can build, and show initiative when you can. You aren't hopeless.
I don't know you very well but you seem pleasant to me and I'm sure you could be quite engaging IRL.