I have a P238 - cocked and locked all the time.
It's a little unnerving at first, but I think you get used to it.
Maybe try it with nothing in the chamber for a week or two.
The downside of carrying with the hammer down is
1) in theory it could get pull up and then dropped (I think) which could fire it
2) and it's definitely slow to pull, pull the hammer back and fire. Try it a few dozen times so see how that works.
I practiced with my P238, empty chamber, with a timer. That added about 1/4 of a second to my draw and fire time - pull, rack slide, fire.
I'd rather do gross motions (rack slide) than fine motions (thumb back the hammer).
my advice is worth what you pay for it
Another idea - with nothing in the chamber (triple check please) carry it around, pocket, holster, in your hand, around your house. Keep your trigger finger straight every time you touch the gun. When it's habit, and you never break it, you'll know you won't pull the trigger unless you have to.