Is the general consensus that my W has indeed massively over-reacted to my mistakes?

I find it really interesting that the majority of people I have spoken to in person - and some of them, including my parents, know EVERY detail of what I did behind her back - are all agreed on the fact that after just under 3 yrs of M she threw in the towel. I have not revealed everything I did on here as I'm not sure (a) it matters or (b) I assume it is not appropriate for me to describe on this forum.

This is not to excuse my behaviour. I have remorse, but no longer feel the shame any more, as lots of people KNOW what I did - it's not a secret that I'm fuelling with shame. It's made it easier to deal with certainly.

I get that it was a lot for her to discover. To her I was essentially 'perfect' - probably a really bad thing to think as every little thing I did wrong was seen as pretty major by both me and her (NGS definitely). Then her discovery of what I'd done behind her back for years shattered that perception of me, that I was a 'decent man'.
I AM a decent man - I just let my selfishness cloud my judgement and didn't move forward until now.

If R happens further down the line, so be it (though I'm not so sure my W's sister will be pleased).
Even if it's too late for R and D is final, I know that I am getting better.

I will be AMOAFWL.

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