I have an analogous problem. I cannot spell words which are spelled differently than the way they are pronounced like resteraunt and other stuff like that. I also have weird quirks with numbers and somehow calculation takes me a long time and I tend to make idiotic mistakes unless I am 100% in the moment (we all do, but these mistakes are different from what other people make. It's the same pattern over and over again).

I think that you might have some degree of dyslexia and other co-morbidities. (http://en.wikipedia.org/wiki/Dyslexia#Comorbidities).

Have you ever gotten it checked? An accurate diagnosis can go a long way in formulating a response and finding a solution to this.

I can't even begin to imagine how bad it must be for you, but I do know that if you work at it with some professional help then it will improve in subtle ways. Miracles won't happen due to age, but you will be the richer for it.

Take care.