I have played more online Blitz recently and it was quite some fun, until I encountered what I would call the "blundering phase". Every once in a while, my chess ability takes quite a hit when I apparently lose my ability to think properly. I have lost about 100 rating points online. In many games, I get a winning advantage, only to throw it away with utterly stupid mistakes. I do not know what the root cause of this is, could it be psychological? I'm doing daily tactical exercises between 20 minutes and one hour, so that can't be it. Do you have experience with this and maybe can propose a remedy that has worked for you?