Fulfilling their Christian duty

Image by freefotouk via FlickrA letter from Matt

I'm 18 years old and have been brought up in a fundamental (Presbyterian) christian background since the day I was born. My parents are both devout believers as well as my older brother. I was a firm believer myself, although I struggled through many things like drugs, porn, and bad habits like swearing (all the while believing in god and trying to live it). I have also attended Christian school all my life, and am currently a senior in high school (where I am in an apologetics class!)

It was just over the last year that I really began to question my faith, and about 3 months ago when I utterly abandoned it. At first my parents were shocked; my mom cried and my parents tried to make me convince them it wasn't true. When they realized I was serious, my parents made me go to a Christian counselor, but it was eventually my choice to end this. My dad then said he was going to make me read things like "A Case for Christ", but this did not come to pass.

Currently my parents still pray for me constantly (fulfilling their Christian duty) and talk to each other about me when they think I can't hear them. My dad still tries to have discussions with me about faith, "in a non-confrontational manner" as he puts it.

It is only a few months before I leave the house to go to college, but it is maddening putting up with this at home. I know I am right and that they are so blinded by their faith, but they are so sure in their faith and think it is their responsibility to "save me from going to hell".

What should I do to cope with this?

Thank you for your time,