That's true, but at one point you have to make a decision to either keep holding or to sell a part of your stack to buy back more Bitcoin lower.

What you have to remind yourself of is that you can't time the market. You will likely sell below the price that will turn out to be the top. People tend to get upset because they thought they sold the top, but it turned out to not be so. What some of them do is buy back in higher, and then get trapped waiting for the price to go back up while it's going to go down more.

Point is.... Stand firmly behind your decision to either secure profits or not. Don't act out of panic afterwards. You'll lose money.