Are you determined to split, or is there hope here? The lessons on the Improving Board can help. I used them to help reduce conflict while we were living together.
Whatever the case, t would be good to start documenting everything, in a journal (weekly planners work well). Dates, times, facts. It can be legally admissible later if it comes to that. Do you and the kids feel safe?
There is no hope and I have been using the lessons to get me through to survive living under the same roof for now. There is no threat of physical stuff but it is the walking on egg shells and not knowing when her current 'good mood' will turn into one where I'm questioned and criticised for things. I have just read another other board about divorce etc and seen posts re how mediation may or not work. I feel like in trying to negotiate arrangements for kids I am the one with the responsibility to know if they will be safe or not. Whilst I am living here I can ensure routines followed etc so there is some degree of normality but once we are physically separate I think I will be worried.