You can even use the mediation as an opportunity to show how commited you are to making sure that she and your son are taken care of. If you need to stall, tell her that you need your space, Im afraid that if you go into mediation now, you wont be able to represent your best interests. Tell her that you need time to think, settle, deal with your own emotions. Then use that time to DB your butt off!
I guess I gave the wrong finger to the wrong man...