I'm glad you were honest and forthright with your W. Sometimes we fixers sugarcoat things too much.
As for your friend's awfulizing, be careful where you let that go in your head. Yes - it is possible that his scenario will occur. However, YOU do have some control over whether or not you have a fourth child. You are in a much better place to prevent the whole dismal picture than you were a year ago.
By all means get some MC or whatever but take care of yourself first. You need to get back more strength to fight for this M.