I think my wife is cheating?

My sex life has been down the tubes for a year and my wife is always on her Iphone. When I hint around or ask she says because I hurt, but looking at all the on line subjects it seems to fit. I know she has lied to me before and will lie even about little things. How should I pursue this? I’ve checked the on line places like spokeo with no luck, and have tried using wireshark to catch network traffic. I’m about to call it quits so I’m asking for help. I’m sure she even uses this site,