I think the separation process can bring out the worst in some people and reaffirm decisions.
That is definitely what is going on with me! I have absolutely no regrets at all, and the fact that XH is being such an absolute a&&hole just makes me wonder why I waited so long. Like, 2 days ago he was asking if I would consider trading sex for help with the "man" jobs (since I couldn't start my trimmer), and today here is an extract from one of about a dozen emails he sent:

"The girls will know who you are even if I dont tell them, your dad walked away because you were too much to deal with and all your friends left you.....look at the common denominator how many people do you know that do not have one person they have maintained a relationship with....grow the hell up and realise no matter what you think in your drug altered brain that you are the problem."

I feel like a much stronger, more capable person since I have been living without him (and I WILL get that damned trimmer started, somehow!). Part of that comes from being so sure of my decision. As someone else said, it is a decision that only YOU can make, but there are other things you can try if you are not so sure - such as counselling and/or a trial separation.