Celsius uses stETH as collateral for stablecoin loan, so they have to pause withdrawals to prevent panic sales that may cause their asset to be liquidated. At this moment I'm not sure what Celcius users can do, because Celcius is CEX. If you still have assets with them, then we are on the same boat, and can just pray to god for this boat to pass through thunder storm safely. Meanwhile, look through other platforms with the same situation, in worst case scenario, this can be cascading liquidations.