I, too, felt bad how the market went this level. But, I wonder if there will come a time when I will say, "I should have bought more that time" referring today.
The thing about these massive downtrend movements is that you don't know where the bottom is, therefore, you shouldn't buy big chuncks of X or Y coin as you'd put in a really bad position if those coin continue to dump. Rather than regreting not buying more, you just start accumulating little by little, it seems like that's the way to go with the current market conditions.