Experience is definitely key in shorter term trades. For the most part, doing all of things needed to make a successful day/short term swing trade can be tough especially when you have to battle with emotion too.

As always knowledge is the best weapon to use against fear. If you know how to manage your trade and your risk and you do as you have said, Set and forget, you will be fine. Day/swing trades should be analysed, entry and exits defined, set and left to play out. If you don't just leave it to play out, you just find yourself REANALYSING and you will convince yourself out of a good trade.