well you have already made one mistake, i suggest taking things slower this time and think more before taking any actions.
you have two options for buying back
1. wait a little longer to see what the market is going to be like. to be sure if this is a long bear market or if it is a long dip that will end soon.
2. buy little by little in big dips. for example if you are about to invest $10000, then buy $1000 when you see a big dip or place low bid orders and see if they get filled. this is of course easier to be used by those who are planning to invest long term.
It's the biggest mistake of all. Virtually everyone who thinks they're going to outwit the market and buy the dips and sell the bumps is fooling themselves. It may work once or twice, but as all great investors will tell you, the market can remain irrational longer than you can remain solvent. The only people will win in crypto investment are those that have a well defined investment plan and hold long term.