Is it time to leave my husband who is addicted to ?

My husband of 13 years is addicted to . It started about 10 years ago. I didn't realize the addiction until probably 5 years ago. I didn't really see anything that bad about it early on even though I knew he was on . But it is now ruined our marriage. We have not had in over 7 years and now I find out just how much he's been on . It started with just the soft , then went to gay and now teen porn. He swears he's only looking at 18+ porn sites, but I don't believe him. Just recently I found some pictures of young girls, though not porn they were pictures of 11, 12, and 13 year old girls on his computer. He says there is nothing wrong with that and he was just working late one evening and downloaded them. I asked why would a 53 year old man even want to look let alone download pictures of young girls on his computer. He didn't have an answer. We have an 11 year old son and it just disgusts me that he would even go so far as to download them. Now they were not naked pictures but all I've read on the subject states that it starts with just the soft porn then that wears off and they need a bigger thrill so they go further ... which now scares me that he's getting into young girls.. I think though he might not be looking at porn for the young girls he will soon as the thrill of everything else has worn off. He's been to two psychologists and quit...has continually told me he would seek help but doesn't. We fight all the time about this but I really think he's blaming me for his addiction. He tells me that it's complicated why he got into porn and that part of it was my weight gain. Now I'm not obese by any stretch of the imagination but I'm sure I'm not as attractive to him as I was. He says he doesn't want a divorce yet I see no real progress in him getting help or wanting to get help. I really think he is blaming me and as long as the blame is elsewhere he justifies his reasons for being on porn. My take on it is that he really has no interest in life in general. He does workout constantly and is what he says a gym rat. This started a couple of years back and basically his live is work, working out, yahoo answers, porn and tv. My son and I seldom have any time with him and he always has an excuse why. Had to work late or needs to relax and then tells me it's none of my business if he's tired and needs to sleep. He has no interest in maintaining our home or doing anything with the family. I think he's depressed but he just throws that back at me and says why wouldn't I be living with someone like you. I've never wanted anything more than just a normal family. Work together, play together enjoy each other, but we are far from that. We are like roommates at best. I think I've tried everything to bring our family back together but have failed in every attempt. I don't give up easily but I think it's time for me to throw in in the towel. Would love to hear your opinions.