Do not feel guilty about asking for SS, or what he will pay in CS, or how things get split....BTDT. Bottom line is this is what he wanted...give it to him.
I know when I first started thinking about SS I felt guilty, and a few weeks ago when my lawyer told me how much I would be getting for SS the first thing I said was "that's a lot" and in my head I was calculating to see how he would be able to live paying everything that he has to. She asked me if I wanted to lower it and I actually thought about it for a second. Then I remembered it's not my problem how hard things are going to be for him, he certainly hasn't cared how hard things have been for me, and the kids. So I told her no, if it is to much for him, HE can go through the steps to get it adjusted if he can.
I know it's hard to not feel sorry for them at times, a normal healthy person can't just shut that off, but you have nothing to feel guilty about when it comes to the divorce. What everyone says is true about the divorce process...leave your heart out of it.