Verysky you are not alone. Lockdown has brought everything to the surface because there is little other to do and too much time to think.
By 60 we have all experienced the issues you mention, we've all known love and loss, all been broken and lost a bit of ourselves.
Can't change that. Can't go back. Hopefully learn from those experiences but it doesn't mask the pain, guilt, regret.
I find losing myself in the garden, plants, flowers, nature, wildlife lifts me.
I think also we realise that mistakes made in you're 30s, 40s, 50s - more often than not we've time to attempt to put them right. Now, in the autumn of our lives, when we get it wrong we may not be given the years it takes to do that.
I suppose what I'm saying is you're far from alone with your thoughts, at any time but especially during these days of lockdown.