Self doubt and uncertainty is all conjured in your prefrontal cortex by your consciousness, this is why animals purely act on stimulus response from the central nervous system.
Your reactions are only reptilian in nature, so don’t be so hard on yourself, stimuli from the medulla oblongata and cerebellum control your fight or flight and emotional reactions, just like animals!
All rational thinking is done in the neocortex, Again, only humans have this part of the brain!
make a decision and stick with it.
Ignore all the doubt your consciousness keeps in.
Look after your brain!
+drink more water.
+get 8hrs sleep.
+eat more Meat & Mushrooms.
+blueberries are life.
+go for a 20min walk in the sun every morning.
+eat less phytates and lectins. +read an hour everyday.
+turn off all bluelighting and ultraviolet rays at sunset.
And Watch 99% of your problems disappear.