I'm scared because price Bitcoin down, I do not know what to do with Bitcoin at this time

Why scared? Remember that before the surge we are sitting around $700-$800 as far as my memory is concern. Instead, take this as an opportunity to make another rounds of buying, yes embrace the dip as it was normal.
Advice? If you think you missed the train of selling price then just hold since it's just the same risk. While at the same time just continue with your method to earn bitcoin. Accumulate more and more. If you don't need to use your bitcoin then just let it sleep.
No one knows what will happen in bitcoin price so better play with it.
Easier said than done, I feel tense and worried. If Bitcoin prices continued to decline, I will lose a lot of money