Seperating but living together

It is 9 months since I told my wife I was unhappy with the lack of emotion in our marriage. Her response was to say we should split up and then join dating sites. After several dates and flings within the first month she met someone "special" who she's been seeing ever since. I am very lucky that I too now have started seeing someone very supportive that I knew through work. We have a gorgeous 4 year old boy who is my life. I struggle with how things will change with another man in his life. Another problem is we are still sharing our marital home. As neither of us have anywhere else to go and money is very tight. It is extremely difficult living seperately together. And she seems to show no sign of making plans for the future. Happy for me to still sort out all the finances etc. She continues to work only a few hours a week and I think she expects me to support her financially in her new life. I really don't know where to start with moving things forward. Can I start a divorce whilst we still live together? I am afraid to leave my home as I here so often of the unfair difference in quality of living once that happens. I'm sure she would be more than happy to carry on living in our house whilst I pay. I also enjoy that I'm still with my son all the time but know this is not sustainable. I feel my health deteriorating with the stress and am struggling in my job too. I have one foot in my future and one firmly in my past and feel myself splitting further and further in two.

Hallo and welcome to Wikivorce

Yes you can start divorce proceedings, you need to be living separately though - ie not sharing a bed, or meals etc.

As for how the finances will be sorted, much depends on your son's needs. His housing need will be a priority and if your wife is the main carer (it sounds like she is as she works parttime) her housing would be with him.