Help! Trial separation

Hi there I'm new to this forum , I have myself in a dilemma. I have been married for 2 years and I have been with my wife for a total of 4.5 years. Things started off really well for us and we were really happy. We always had our little disagreements , but we worked through them. Before we got married we were advised to meet up with a couples psychologist to work through some of our issues . I have always been a clean freak and a hard worker around the house were my wife still lives outa washing piles on the bedroom floor etc . Anyway we meet with the shrink about 6 times and focussed on our Communication With each other and things we need to work on. We got married and had a son a year later. We both work full time , and have family to help out with child care during the day. Over the last sort of year things have been getting out of control with our marriage. My wife has got so controlling over me. I'm talking getting txts everytime I use my bank card , if I get haircut etc it feels like I'm under constant surveillance. On top of that if someone rings me on my phone she will hit the roof and give me the cold shoulder. She doesn't like my parents and gets upset when i take my son around there to see them. If I drink a beer after work that is problem also. It got to the point that I was doing around 80% of looking after our son, if I was inside taking care of him , I would be getting yelled at for not doing something right with him. Or for checking a txt on my phone. In the end I decided it was better to look after him in shed away from the drama. We have been back to shrink for the last 8 months and nothing has got better only worse. We are both on medication.The other day I reached breaking point and decided to move out , and that I wanted a separation. Her father manged to convince me to have a one month trail. It has been 3 weeks now away from each other and just seeing my son whenever I can. We are both seeing psychiatrists to work on our issues. The problem is that the other nite i fuked up bad and had a one stand. As to me that was a way of ending the relationship . I feel so guilty for what I have done. Not so much for my wife but I hate cheaters and that is one of my vaules to remain faithful. I told my wife that we could try and resolve our marriage problems but now I feel like I've really ended it. I can't tell yet about the one nite stand. It's killing me inside and I'm an emotional wreck. She tells me she loves me and that we should try make it work as we have only been married for two years. But I have been so unhappy for so long I don't even know how I feel anymore. Our would say our marriage has been one constant disagreement with little compromise . I'm not perfect by any means but her controlling and emotional bullie tactics have taken me down to the lowest point in my life. What to do? Any advice would b great?