This.Just remember, it is only a loss on paper when the market dips. You don't lock in the loss unless you actually sell when down. If you are investing long term, hang tight!
When thinking long term - invest in the stock market. Buy good companies (ensuring to allocate wisely, not owning too much of one company, and maintaining a level of diversification in line with your comfort level on risk). Keep feeding them on a recurring basis, and buy into them more when/if they dip. Don’t sell until years down the road when you actually need/want to - you’ll be amazed at how much you’ve made.