Sophie, God's Child gave you a good response. I would add, from the biological point of view, that the human race itself has something called a building genetic load -- that means that heritable mutations are building up in us. The mutations you are the victim of are just some of what we have accumulated. WHATEVER you are, you are a sibling in Christ, and in heaven none of us will have to worry about the human genetic packages we were born with and have to deal with daily.
We have five adopted special case kids. They are grown now, but they each had 'packages' that needed to be dealt with one way or another. And all I could ever say to them was that first, God allowed it for reasons of His glory -- which may well be connected to His using you to be there for others like you who are not believers and are searching and hurting -- and, second, that we are each dealt a 'hand at cards' which must be 'played out' the best we can.
It's not that God caused your condition, but that He allowed it. There is a difference. But He would not have allowed it if He did not plan a use for it. You are His because you are a fellow-believer. Ask HIM what He wants of you and then do it. Don't worry about those who are also confused and afraid because of the evidence of what sin has done to the human race.
We have found something interesting where one of our children is concerned. Chris was born addicted to heroin, but that was not nearly as awful as the fact that, a year and a half after we adopted him, December 7, 1987, when he was a little over 3 years old, he came down with sudden onset viral pneumonia which escalated to encephalitis within a week as the virus migrated to his brain.
We once had a bright happy toddler who was in love with life. Today we have a twenty year old whose IQ cannot even be measured (therefore under 20), who will always be in diapers, and who cannot speak and is autistic. His mouth hangs open most of the time and the drooling can be a bit of a mess when he forgets to swallow.
What is interesting is people's reactions to him. There are those who don't mind at all and will hug Chris back (he's a great hugger) or just laugh if he tries to pull down their pants a little (if you can change my diapers, I get to help with yours, right?). There are those who are not overtly antagonistic but also not friendly. They just sort of keep their distance. And then there are those who are as disgusted as anything that we would expose people to this bit of damaged humanity.
Chris exposes people's inner characters. He is as good a thermometer as I know for this.
I imagine you experience some of the same regarding yourself. It does tend to strip away hypocrisy (or basic Christian immaturity), doesn't it?
God bless you.