Em I over reacting? ?

Me and my wife been together for 10 yrs. We have 2 beautiful daughters. About a mont ago. We had a fight. And she left the house. Since then I promise I was going to change my attitude that been the reason why she left and wants a divorse. And yesturday she brought the kids home to spend time with me. I saw a change to show a lil of what I change. So I gave her roses I bought her a ring And give her a card. I told her that even do we get a divorse I will still show her my love and give her roses as much ad I can. Wich I never did that before. Well I spend time with the kids play with them and my wife fall sleep on the sofa. And her phn fell to the floor and ring. She had a message. I didnt meant ti see the message but I did. While I pick up the phn. And it said. Where are you babe I miss you. That just really broke my hart and I confronted her. And she said she is not cheating or seeing anybody that the text it's from a guy the he likes her. But she is not seeing him . Anyways. I feel so betray and angry even tho she says she would never do that while we are merried. Wich I don't knw what to think. See I couple of yrs back her sister was kill by her Housband and suppousylily she hAd a friend that he like her but she was not having an a affair with But her Housband did had an affair with somebody else and it all came out on a fight and he shot her 3 times. And I knw my wife or ex wife always thinks about her sis. And I don't knw if she doesn't want to tell me that she is seeing somebody afraid I may go crazy wich Im. Or she is really not cuz she said she would never do that. If anybody can talk to me specially any specialist. ? I appreciated