Mobile phone search

Hi, I have been with my partner for 17 years and we have lived together for the past 9 years my problem is trust. We have both been married many years ago and we did in the early days have a few ups and downs but settled down and I felt we were quite settled and happy. Over the past two years I would say I feel our relationship is not the same. I have found out he was texting another woman which he would not discuss at all and that then stopped, our sex life is non existent and he appears to have no sex drive or interest. If I raise this topic he would get quite defensive and say its not the b all and end all of a relationship and he was not worried by it. He does have a long term problem with herpes which recently flares up all the time which again impacts on our sex life. He says it's made worse by stress and illness such as a cold. But I recently found on his mobile, and yes I know why am I looking, a text from an unknown number quite sexual and then I found a message to what I have found to be a flirty online dating site. I am so angry upset and devastated. He knows I am upset about something and I have said I feel very unloved unattractive to him and he says I am not but I just can't tell him that I have looked at his phone. I am an educated woman but just do not know what to do next

Actions speak...his are and there are confirming your suspicions. Intimacy is one of the main keys to a successful relationship..so is trust. Regardless of what's on the phone and his personal health, it's this lack of trust and intimacy which tells you the relationship is over. He owes it to you to discuss issues within the relationship which affect you both but you owe to yourself to move on from the relationship because it's become a one way street where it's all about him. You are no longer on his radar, there is no flowing communication...only defensiveness from him. That alone tells you to move on.