Am I Past This?

While living in Connecticut, Brian and I went to counseling for a brief period after my brother died. We were both dealing with something neither one of us wanted to deal with, nor were we prepared to deal with, the death of my brother. Losing him changed me. His death has changed the way I think, the way I act, what I want out of life. Losing my brother has impacted every single aspect of my life, in ways I never thought possible. Some were good and some were not, but taking the good and the bad and working through them both will be a life long journey. During counseling I opened up to our counselor in a one-on-one session about something I had been keeping locked deep down in my heart. Something that I've struggled to face the possibility of, the uncertainty of, the fear of, something that has kept me from being able to move on.... When my brother died I found out the news in the morning and flew home later that same day. It wasn't until after I got to my parents' house that I was told of my brothers' body being burned when his truck caught on fire. From the moment my mom told me that and even after she tried to assure me that he was already gone when his body burned I have secretly feared that my mom was wrong. I have had nightmares that he was actually alive, but was trapped and because no one was around to rescue him he burned alive. It sounds horrible, I know, but this was my fear. I told the counselor all that and he assured me that he must have been gone before this happened. Our counselor used to practice law, he was a defender, a prosecutor and eventually became a judge before leaving the law behind and starting a counseling practice. He told me that the coroner could loose his license if he falsified records or lied to someone about the way a person died. In my grief, that line of thinking never occurred to me, so I was relieved. I thought I could finally lay this to rest and move on, but lately it has started coming back to me. Out of nowhere the notion that he was still alive when his truck caught on fire invades my thoughts at any given time during the day. I truly thought I was past this, but now I'm not so sure and I don't know what to do about it. It's not as if I have complete control over all my thoughts. So what do I do now?