Be an opinionated motherfucker. I had this same issue. The solution? Figure out who you are and stick with it. Because of years of bullying, I spent even more years crafting an outward persona that I embodied for socializing. I took up flying, scuba diving, other esoteric bullshit all to feed into this persona I crafted.

The healthiest thing I've ever done was abandon that persona.

Nowadays, while I've had those experiences, I understand flying was never really for me, nor is scuba diving or poetry or whatever else I thought of as "acceptable." So, now, instead of doing and talking about things I thought of as acceptable, I talk about things that legitimately interest me. I'm a human being with interests and beliefs--I've formed opinions on just about every common topic around. I freely share those opinions with others and hear what they have to say in turn.

A conversation at its very fundamental level is nothing more than an exchange of ideas, an ebb and flow of information that shows the other person an aspect of who you are and what you believe. To be successful at doing this, you have to first know who you are and what you believe. In my case, despite actually doing these activities, I was never really the flying, scuba diving badass I thought people wanted me to be. I was a human being with other interests--confidence and comfort in who I am now and a willingness to share this person with others is what helped me above all.