I usually do not think before I react. or type for that matter.
Well, this will give you plenty of practice. You can start with anything that comes at you. Then you have to force yourself to breathe, count to ten whatever works for you, first. It's ok (and in alot of cases good) to say I'll get back to you on that.
You don't have to have an answer/solution right off the top of your head. I think men are hardwired differently as far as reaction goes (the whole protector thing), these aren't life or death situations (regardless of how it feels, one or more mistakes won't make or break anything), so push yourself. You can do it.