Total honesty

Okay, so here goes. I've never done this before, but I need a place where I can just be, and not worry about what people think of me, while still getting feedback. 
In my everyday life, I have a lot of people look up to me, and certain expectations to live up to. In addition to that, in my family I'm the "good egg" in a family of screw ups, so I feel that pressure to always know what to do and to always have the right answers. 
I knew today coming home that I needed to reach out. I stood on a bridge, looking out over the water,  and not for the first time wondered what it would be like to jump. I have had that as a passing thought before, but this was the first time that I stopped, envisioned it, and seriously considered it. There was a part of me that always knew I wasn't going to do it, but enough of me was considering it that something needs to change. 
The last few weeks/days/whatever have been hard. Recently, I've realised how selfish of a person I am. I am constantly looking at other people and telling them what is wrong, and what they should do to fix it. I have started working with a close group of people who run an organisation, and I find myself constantly getting in the middle of conversations. Learning things about people, and then talking about it. The excuse is that these people need to know, but I'm not always convinced thats true, or if we're all just a group of gossipers. 
Ever since I was a little kid, I would lie about stuff. That hasn't stopped. It isn't even big stuff, and I almost always get away with it, but I don't have a single person in my life I'm honest with. Even people in my life who I'm closest to have no idea into the mass of stuff I keep hidden. I grew up in an abusive house, and then I moved quite a bit, so I'm really good at keeping people far enough away that they can't see what's really going on, but doing it in a way that they think we're quite close. 
I always think the worst of people. I'm constantly ready for them to give up on me. I'm scared of ever relying on someone, becuase I can't imagine a scenario where they would care about me as much as I care about them. I'm single, and a big part of it is self sabotage, because I know how to be on my own, but being open and honest with another person scares me. The fear of rejection either makes me defensive, or keeps me from even wanting to try. 
I want to fix this. I want to be the kind of person that people think I am. I want to think of others first, and be kind, and have close friends. But I don't know how to get inside that circle.