To leave or not?

I have been with my wife since I was 17. We have been married five years now. Four years ago we had a child and shortly after I began feeling unwanted. Around two years ago I began cheating. I felt unwanted and unloved, undesired and useless. My wife suffered badly from depression and began acting out verbally and stopped showing emotion toward me. Everything I do is criticised and even my family day she shows no love toward me. All she does is take from Me. It's complicated to explain, but she has had a hard life. I out my own emotions and needs aside and focused on her mental health, now mine has suffered. Essentially, I seemed comfort away from home whilst providing emotional support at home. Atleast that's my excuse for cheating.

My wife's mental state has recently begun to improve and I have voiced my issues to her, we don't talk, when we are together we talk on our phones to other people, we have sex maybe once every 8 weeks and we get angry at each other over silly things. Recently during an argument she threatened suicide and told me it would be my fault if she done it because I had driven her to it. She said this infrint of our three year old.

und 5 months ago I met a woman who has shown me so much kindness and I have fallen heavily for her. However, she is leaving the country in a few weeks for work and won't return for a couple of years.i want her, but should I leave my marriage for her? I'm confused and scared