Your upbringing can definitely play a significant role in how you handle relationships. A lot of people including myself only grew up with one parent and never got to see what a healthy relationship really looks like. My mother has given up on relationships and chooses to be alone after being mistreated by my father and other men. I always encourage her to try and find someone new but she scoffs at the idea.

I messed up a lot with relationships at first. I would actually do the same thing as you do when I look back on it. I would constantly put myself down and ask them multiple times why they wanted to be with me. It screwed up so many potential relationships for me. Over time, I realized it wasn't the girls fault for abandoning me, it was my fault for pushing them to the point where staying around was detrimental to they're own personal growth. This sounds like the same side of the coin you're on.

Again, you're different from the girl I mentioned because this isn't something you enjoy and it eats you up inside. You want to have a love interest, but this subconscious insecurity keeps you from making that happen. It's hard to see the things other see in us sometimes. I'm pretty sure that was the reason I pushed so many girls away. I didn't want them to go, but I didn't know how to show them the better sides of myself because all I saw were the negative ones. It's a terrible habit but if I could break it, so can you.

I hate to sound like a therapist, but tell me some things you like about yourself. Things you wish other people would notice about yourself. By giving these good things about yourself some light you're breaking the habit of keeping them in the dark.

In my case, I love to make people laugh. I used to be so depressed I completely forgot about that part of myself. That's a good quality that no one knew about myself. Bring those things into the light a bit more. If you can't find any then you need to allow yourself to create some. Find a new hobby, take a new class, learn new things. I know all of this sounds irrelevant to the problem we're talking about but it's really not. If we don't love ourselves how can we love someone else? Or in your case how can we let someone else love us?

I did that and what I found was that I started to know myself better than I ever did before. Then that instant reaction of pushing people away and not letting them see who I really am vanished. I could finally have a conversation with someone without underselling myself to the point where I wasn't even sure if I wanted me!

I hope that helped a little. I'm just offering how I handled my experience with pushing people away.