I forgot to say...

As above OK maybe you had a right to stay in the house and not be "kicked out" but I think that had you refused to go would have made this situation a lot worse - you two are adults and if you choose to spend far away as possible from or spent every moment arguing and screaming at what impact would this have had on the children?

For 2 parents who are no longer together and tensions running high does not implicate a loving safe and secure for children to be stuck in the middle of.

You did the right thing in my opinion by leaving. Sadly she never thought of the implications of just quickly moving another man into the family home - children need time to adjust to a parents separation. But you can not dictate who she dates or moves into her house unfortunately. Sadly some women just do not put the children first.

You should have had a lawyer the day you left.

The same thing happened to me, I was in a 6 yr relationship, have 2 children and unforunately, she brought the guy over before she kicked me out, in the middle of winter (at 1am in the morning). I can't give you much advice on how to get over it, as I'm still in that boat with you... only I have to see HIM every time I see my kids. PPL tell you to not think about her, but that is like telling a fish not to swim. You need to find a hobby that keeps your mind focused on it. I took up Online Gaming in MMOs 9not the best answer I know) but it helped me think of her less. I still think about her when I sleep, so I try to put the TV on and watch some movies with lots of comedy or something, nothing about romance or sex or anything. Eventually you will fall asleep.