Have you ever bought the dip, but then the price breaks through the support and continues dropping deeper for weeks or months?

Well, I have done it before.
Even the best traders make mistakes a lot of times. It's just that you make sure you have some sort of "contingency plan" if your initial plan(like buying the dip too early) doesn't go well; like having more cash ready for more dips and such.
I have bought bunch of altcoins & bitcoin itself ofcourse for the third try now after cutting all my losses at the $55k level and $46k level.
thought it was the dip before we could go for another skyrocket to $100k , it cost me 15% × 2 losses . 30% of my portofolio gone for good.
now the last try i could go for $41k and so do with altcoins that hits so hard. extra cash needed at this point. 50% target up for my portofolio!