These decisions can only be determined by yourself, while I will only provide suggestions that may help you. Investing in the crypto has many chances whether it's to win or to lose, the red market is a good opportunity to buy more coins but we do not know if it will turn green or just keep red.
One thing I have done since the red market is that I wait some time to test whether there will be a change in the market or not, after which I decide to buy more coins when I see an opportunity for a green back market.