Does my character reset when I change difficulty?

So I'm told at the end of act 3 I can choose to change difficulty and reset my quests. Will this make my character level 1 again? Do higher difficulties drop better loot? Do I keep my stash? Also I'm on hardcore mode do I get any benefits from this over standard? Thanks!

ur character wont change, also u keep all ur items and stash.

u will restart in act 1 cruel, where the monsters simply match your level. yes they drop better loot

no benefit for hardcore but the thrill u want from it