I'd like to echo what Rooksers has said above. It is normal to feel this and want to figure out things.

'Reset your life' is quite apt. Yes it is to an extent a forced reset but you have to believe that things will be good and better. Looking back is normal as well; I do it sometimes too. How you could have acted differently, and how things may have panned out. Hindsight is great but it's best not dwelt upon; just look ahead and be excited.

Me - 36, W - 32
No kids
T - 8 yr, M - 3 yr
Discovery - 14 May 2019
S - 25 May 2019 & D bomb - 29 July 2019
D & House sale final - Feb 2020