The market usually drops without fear when you are holding USDT. Those BTC buyers at high prices that are down are certainly scared.
There is nothing to worry about the falling of the price. Now it is normal and you will see pump again tomorrow in the price. So dont be panic and be patient while holding your coins for long time. Cryptocurrency investment is not for short time and you should keep this in mind before investing in bitcoin. If you are impatient then this world is not for you. You should invest your money in some regular business.