Hello NotSoHappy,
First, it takes a strong and honest person to look at things as they are , you are to be commended. Second, you are just an imperfect man like anyone else, don't be too hard on yourself. I was similarly abused by a female cousin for a period of 2-3 years almost the same ages as you and your cousins. I likewise didn't realize how much I had been affected until the last year and a half. Looking back, when I was younger, when my wife and I were dating, I was extremely insecure and this often led me to look elsewhere for female attention. More recently and what made me finally realize something was wrong is that I started having serious trust issues with my wife and for no reason. I also became very depressed. I have always been extremely critical of myself and lacking in self esteem. Prior to getting married, I was very much into auto racing, and I was extremely competitive which on more than one occasion led to post race altercations. I have had issues with anger and bottling things up until I would let go in a rage. I say this not to compare or even to say I have any idea how you feel but to let you know you are not alone in your struggle. For me, I found a great therapist and applying the direction given, I have had major improvement in my self esteem, trust, and my marriage. Finding this site has also been very encouraging. Please hang in there and keep working to heal and make positive changes.