What is the fear/paralysis that occurs before doing an irreversible action?
Philosopher Walter Kaufmann calls this fear "decidophobia", but I have never read and cannot find any psychological publications using that term.

If you think about the phenomenon, it becomes apparent that anyone can clearly observe when a person hesitates to decide, but even that person herself could probably not clearly identify all the emotions that accompany this behavior, and, if there is fear, what the exact object of that fear is – the fear could be of anything from deciding between two equally desirable alternatives (fear to decide) to the outcome of a decision that is in fact already made (fear to finalize the decision and face the results).

Psychology therefore prefers to study observable behavior and calls this behavior "decision avoidance".



The above answers the question you asked in the title of you question. Your post itself describes a bundle of symptoms that to me are reminiscent of what persons with obsessive-compulsive disorder experience. Many such disorders begin with a worry that something was forgotten and lead to extended rituals of checking for hours if the water is turned off or the lights are out. The problem here is that these people become increasingly incabable of trusting their perceptions and have to repeat certain actions until they are finally convinced the thing was done.

An example is of a woman who frequently goes on business trips and, upon returning home, has to read the name of her city several times loudly letter-by-letter at the airport to get the feeling that she is actually there.

Since I know nothing about you beyond your post, your problem – if it is one – is hard to diagnose. If this "fear to decide" affects your well-being, I recommend you go see a psychologist and talk to them about it.