I wish you could step back and see your situation for what it is. That is what a good therapists could help you do. You have had the most extreme harm done to you, and have ever since been without an outlet for all the emotions this raised - anger, fear, confusion about sexuality, mistrust of how to handle intimate and family relationships. When you are molested, all of you is molested, and all that hurt has to go somewhere. To me you sound like someone with tremendous anger inside you at what has happened, but with no way of expressing it. So you have turned it inwards, hence your fear, fealing of unreality, self disgust, worry about others seeing your private thoughts. I can appreciate that it may be hard to trust a counsellor as the one your sister saw seemed to break confidentiality. This may have been for good reasons, as they thought you were at risk, but seemingly was not done sensitively. If you do talk to someone yourself, and I hope you do, explain what happened and maybe lay down some ground rules before you start confiding in them. Meanwhile you need to find more outlets for the way you feel. If you are able excercise is a great emotional leveller - maybe a good session with a punchbag will help! Martial arts and/or yoga train the body and mind to handle extreme emotion and find peace. I would suggest meditation, but I think you are currently not focused enough, but please prove me wrong. You have a good life to lead, and you deserve better than being held back by the emotional fallout of an incident which was not your fault. There may come a time when you want to confront your molester, but first get yourself sorted. You are far more important than them. Also, be assured, behind the most angelic and calm people even we all carry extreme and bizarre feelings, it's part of being human. They drift through our minds, be they killing a nasty boss, harming a loved one, enjoying other people being in pain.... Somewhere in all of us is this aspect, but it is only inside us, and doesn't make us bad people. Your experiences have been more extreme, so your private emotions are more extreme, but they are private, and you are entitled to think whatever you like. So don't worry about extreme thoughts. You do though need to regain control over your fears which are preventing you from living life to the full.
As a final thought, if the person who molested you is currently a danger to other young people, please think about contacting the police. They should handle this sensitively. You do though need to think through whether you can get evidence, which may be difficult, or your sister to testify. I mention this as not knowing the severity of what happened it would help others who may be future victims. Think about it.
Check out the Abuse Support forum too, you may get support there from others who know very much what you are going through, and ideally reassurance that what you are experiencing is very common in your circumstances.
I can tell from what you have written that you have been through a lot, and my sense is that it is overwhelming to deal with for you right now. While I cannot give you any definitive answers, I can say that the thoughts that you are having are not uncommon for people who have been molested, including the self-criticism, the difficulty focusing, the thoughts of "being gay or incestual," as well as the feeling that nothing is real. I cannot stress to you enough the importance of talking to a therapist about these issues if you are not already doing so -- at the very least, it will give you an opportunity to talk to someone who will be there as a non-judging support to you.