Porn Addiction and Polygraph

[Syrus]

I'm applying to be a firefighter and the Fire Department requires that I take a polygraph test. One part of the test that I'm worried about is sexually related. I have a history of being addicted to pornography which lasted for six years. I started when I was 13 years old. It became a never ending hunger. Right after I turned 20, I finally decided to quit watching porn. I realized that pornography was taking control of my life. It's been about 10 months so far since I stopped, which I'm very proud of.

I never have viewed child porn. However, when I was 14 years old, I tried to find porn that had 13 to 16 year old girls, but I never found any, thankfully. Also, about a year ago, when I was 19 years old, my friend showed me some naked pictures of a girl he received from her. My friend was 17 back then, and the girl was 16. The pictures were sent through his phone. While I was viewing the pictures, a few minutes later I realized that she was a minor. I also realized that I was violating my porn withdrawal. So I immediately deleted those pictures from my phone. When I was viewing the pictures, I forgot the fact that she was a minor. I don't know why he sent those pictures to me knowing that I was a legal adult. I guess he forgot that I was an adult.

My question is; if the polygraph tester asks me if I have ever viewed child porn, how should I answer him? If I tell them about the 16 year old girl's pictures, they might think that I'm a pedophile. and will report me to the police. Also, will the polygraph tester ask me if I have a history of sexual related addictions? I don't want the Fire Department to disqualify me because of my former porn addiction.