The sale may be done, but the tax year is not. Depending on your facts, there may still be decisions this year that affect how the transaction is reported, how income lands across years, and how you pay estimated taxes. There is no single universal deadline; it depends on what you are considering.
It is also normal to feel unmoored. Give yourself room to decide carefully. Proceeds parked in safe, liquid holdings while you plan is a common and reasonable first step.