Troubled About Feelings For My Cousin

Troubled asks :

This concerns a certain aspect about me and a friend. We are actually cousins but we met each other for the first time only when I was 16 and he was 19 because our parents did not keep in touch.
There was an instant connection then and ever since we have been best friends. Now I am 31 and he is 34. In all these years, we hang out or at least talk to each other almost every day. Being first cousins, the thought of being attracted to each other never occurred to us.
So we are just good friends. But over the past few years, I started developing a resentment towards him because of his dependent nature. From the beginning, all his friends are my friends and maybe because I am very good looking, I get invited to parties and social circles to which he won't be a part of it wasn't for me. But this I did not mind till until a few years back.
I have had torrid relationships off and on and I often found him unsupportive of these (probably in some case the guys were not up to my standards or his) but I understand that he was being protective. But meeting people, having my own life without him began to be a problem.
I am a screenwriter and even if I do have a wide circle, I meet very few people and him always wanting to hang around me, being there where my friends are made it impossible for me to make any new friends. Besides, he has a few problems that irritate me. He is insensitive and sometimes selfish. It felt like I am always the one who is making adjustments.
Because it is my nature to not say no, he gets away with most of these things. Things changed though. I decided to start saying no and at one point it gave him no other option but to go out and make other friends. He, for the first time made guy friends.
But there was a time I was in a relationship and he would get so jealous that he was being bitter, always seeking self-assurance to an extent that he would come across as conceited and brash.
It was a time when I was very frustrated that he never is successful with women. In all these years, he never once went out with a girl. His expectations are very high and only a lingerie model would make do for him while for some reason he is unable to make success with even just an average Jane.
So the problem starts here: I was going through a dry-spell work wise and my relationship was on the rocks and to add to that are his little problems.
So I decided to talk to one of our aunts who is open-minded and is usually interested in people. She is close to both of us, to him more so because she teaches him the guitar. I met her one day and vented out about the problems I had with him. I was hoping she would tactfully tell him about these things so he would change his ways. I may have been condescending and judgemental when I was talking about him to her.
My intention was not to bitch and gossip about him though. But she never mentioned these things to him when I wanted her to. Months later, we ourselves talked things out and agreed that we won’t get into each other’s hair. Things are ok now, maybe because I am also much more tolerant.
But just recently she spoke to him and told him the things I said more in the manner of proving to him that I was saying bad things behind his back. I told him what had happened and things are still ok between us but my conscience is troubled. Is it really wrong to talk about the problems we have with the people we are close to, to others?
Should we always act as though we are supportive of them in front of others even if we are not? Am I a bad person to think that I will get a sympathetic ear when I am venting it out on my friends? I think I have done this to a couple of other friends too. Please help