Can I sue for fraud if husband knowingly used me for my money?

My husband left me and wanted to end our marriage 2 years ago. We separated. Then out of the blue, he said that he loves me and that he wants to make this work. He also wanted to renew our vows. That was on June 15, 2015. Shortly after that, his credit being poor, he wanted a new truck and did not have the credit so I cosigned for him and lend him $5000. Then a year and a half later, he said that this isn't going to work, that he doesn’t love me anymore and asked for a divorce. I found out that he opened numerous credit cards and used my credit to get them but the biggest thing was from the time he moved back home including 2 hours after renewing our vows, he was online with several dating sites as well as multiple porn and prostitute sights. I know this because one day when I was away, he broke into the house and was quite surprised when he turned the corner and my friend who was watching the house met him in the hallway. He said he just came to get my computer for a day or two. She didn’t let him take it but when I had, it looked through found all the sites on it. He erased the history but forgot about the cookie trail. He obviously fraudulently moved in to take me to the cleaners. Now, he says that I make more money than him and I will have to pay up. What can I do? He doesn’t know I know of all his extracurricular activities. I am 64 and our children have long gone.