Guys, I know I'm stupid because I'm asking myself, in both instances, why I didn't sell high and wait for Bitcoin to come down and buy again?
Because nothing is certain. Because you don't have the confidence for it.
You should have had money at the exchanges when that happened. Would you have been waiting until the right moment or would you have been selling too early or too late?
Why did't you sell yesterday to buy back today, so after the heat lowered? Do you have a certainty (or something close to that) on how low Bitcoin will go until it'll rise again?
I did some tiny-amounts trading in the past. I've got the things right 2 times, 5 times, 10 times, then I've got them wrong and wasted most of the earnings from 20-30 of times getting it right.
I learned an interesting thing: trading is not for me.
Maybe this answers to some of your questions.
Of course, you can get some small amount and see how it goes. You'll need many trades to get the confidence you can do the things right in most of the cases (don't fool yourself, you'll make mistakes too).