You pulled out of the market for a reason that may reoccur. Maybe your allocation is too risky for your personality/situation. If so, getting back into that same allocation might just result in you being scared out of the market yet again at some point in the future. In other words, over the past 8 months, you might have been better off in a portfolio of bonds, REITs, preferreds, and utilities rather than, I presume, cash.
There are 2 possible solutions:
1) Change behavior/attitudes so that risk is easier to stomach. E.g. consume less financial "news" and opinion or check balances less often.
2) Change portfolio allocation so you'll never bail out again. Maybe that means a low-volatility portfolio that will yield less than the stock market, but more than you investing in and out of the stock market. Maybe that means ex-US stocks so that the news is farther away. Or maybe you need to become a landlord to better control your returns.