I’ve been preparing a campaign group for one of my friends who hasn't been able to get a solid group going. 

However, one of the people I asked has been... incredibly pushy and forcing me to make decisions I don’t like. All of the other players have told me they don't like his attitude, and I’ve been avoiding the problem because I haven't been able to figure out what to say... but when he told me to just up and deal with it and not argue, I’m starting to lose my mind. 

Please... someone help. What do I even say? I don't want to come off as rude but I don't know how to deal with this...