Don't give up. One day in the future when your good you'll look back on this day with amusement. If you get frustrated take a break, come back to it later and trust me it will feel a lot better. And obviously just repeating the chords isn't fun, so try to find a particular song you like that has that switch in it, and practice it that way, trust me its a lot more fun. But whatever you do, don't give up, one day it'l just click and you'll be able to do it.