Remind yourself that the market undergoes a significant drop almost every year and a huge drop every now and then that takes years to recover.
Go look at the chart of the S&P500 on finance.yahoo.com. look at the charts for the last 2, 5, and 10 years and see just how up and down the market can be. Yes, it might just keep going up, but it is just as likely that something could happen next week or month that sends it down 30%--or more.
Over time the market tends to go up, but it can stay down or sideways for many years at a time. And the next time it drops, the Fed isn't going to be able to haul it back up because they have already done what they can do.