hurtandsad

I have been with my husband for almost 16 yrs. now and we have a great 13 yr. old daughter.
There are many trials and tribulations with any relationship, but ours is unique in that he has a sexual addiction. I have, over the years, tried to be understanding and even involved, but can't handle what he does sometimes. It isn't anything I want, as I see sex as something beautiful between committed partners, but he sees it as sex & pleasure. I do not have any desire to be with another person. He's the one. I love him with all my heart, but am fearing the worst about the longevity of our marriage. I have, over the last few years found him flirting, having online things going on and he goes out & flirts (who knows if there's more) and I have seen emails and phone numbers that I don't know and can't look up. I do not have any family to speak of and don't even know how I would survive without this relationship.
I find myself trying to be more involved in what he's doing and even snooping to see if there's and real evidence lately, but he's got all his stuff locked up tight now.
Any advice would be greatly appreciated.