If it's really your retirement money then presumably you are 20-40 years out from needing it. Cyclical recessions typically last 1-2 years, and even the biggest Black Swan events like the Great Depression last maybe 10 years. By the time you retire you will have largely forgotten about this.

(If your retirement is less than 5-10 years away, you should have diversified away from stocks years ago, and it's a little late now. Most target-date funds and financial advisors do this anyway.)