For what it's worth MelF, I also have too much cash saved circa 470k and I'm about to invest with this volatility because I see great value.
Some context.....
I worked and saved hard to ensure I became mortgage free, and I max my pension contributions. This is crucial because it sets you free from debt. That, in itself, is a wonderful achievement because it liberates you from lots of stuff including anxiety. You enjoy the benefit of living in your own home without having to pay for the privilege of using someone else's money. And you have a very tax efficient asset.
I have invested in equities from a young age and now my portfolio is considerable. It started as a hobby because I liked watching companies develop and I'm naturally curious. Oddly enough, as I looked back on it, a quid for the mortgage was matched by as much as I could save. And companies I liked that performed well attracted more of my savings. And over-time, with the benefit of compound interest, consumerism, economic growth and luck, it increased in value. I rarely sell and when I do, it's only as a result of some fundamental change in the business e.g.competition, margin pressure, pricing power etc. or a major project when I refurbished my home in 2005 which proved to be my best ever investment. And as with any collection of anything, I've a couple of superstars, some consistent solid performers, and a few dogs. I review the performance once a year, normally in January, because I don't have the time or interest to watch them closely. To my mind, that just causes unnecessary stress and I'm comfortable with my selections. Sometimes, but not often, I cash out of a dog to invest the proceeds in something better. Moreover, I know that I cannot time the market and that there will be volatility in both directions.
I witnessed wealth destruction on an unimaginable scale when the Celtic Tiger crashed. Many people were swept up in a frenzy collecting 'stuff' with borrowed money that beggared belief. The many who lived within their means were made to feel like idiots. And banks merrily fuelled this procession dishing out money all over the place on all sorts of hair brained schemes that a monkey with an abacus would know it would be better to avoid. As a consequence of watching and witnessing the distress this debacle cast on many innocent people who lost their jobs when businesses folded, the crisis took hold, property crash, mortgage defaults etc. I place an even greater premium on cash now than I ever did. In truth, I recognise that my mental well-being depends on my ability to value cash differently, one part security and one part utility by way of opportunity. Better still, I know that surplus cash earning next to zero is not smart. But it gives me a benefit that has no price and represents a modest % of my assets. That is, until I generate too much and find no opportunity to deploy it. And that's where I am now.......ready to pull the trigger because other things I have looked at don't float my boat, with the exception of a small farm which became a romantic notion when Mrs. Fidgety wondered how I was going to mind myself on my own!
Anyhow, forgive the history, it's purely to explain that it's okay to be unsure, to have doubts and to worry every now and then. We all do. Investing for the long-term will protect your hard earned savings and generate wealth. Of that I am certain. I've done it from modest beginnings and now have enough for a comfortable lifestyle in retirement. It's been butchered this week, maybe next week, maybe for a couple of months, a year, who knows until we get the virus killed but it will be fine when I need it in 7 to 10 years. And I will buy some more of the equities I own, and some I have fancied that have retreated to my price point and I will try to stay healthy and enjoy my life.