I empathise with this. Your first para is me for most of my life.
I am better with this now, but I'm not sure what's made me better.
I did a year of very helpful person-centred counselling. I think this helped me see myself a bit more objectively and without so much self-criticism, and to be able to identify feelings better.
I think two realisations have also helped me: firstly that often either way things will be fine. A friend said this to me when I was agonising over whether to end a relationship - "either way you'll be ok", and it was like I'd never considered that possibility - I thought there was either the 'right' decision or, I don't know, some kind of eternal punishment and gloom.
Secondly, I've realised that whilst many others seem happy with 'head' decisions, I am rarely happy unless I've made a decision with 'heart'. It can still be very hard to identify that 'what feels right' thing, but if I can then I try to follow through on that and ignore all the 'sensible' voices if that's possible.
I am still not great - I can prevaricate over even very minor things for way too long, and still have trouble following through when I do make a decision, but I'm getting better. And I don't tend to see my life as a series of wrong choices any more. I did what I did, can't change that, and better to see the positives in the choices I did make than dwell on what else I could or should have done.