My preference is to have a round chambered. If I need it, I am probably going to need it on very short notice, so I want my pistol ready to go when I draw. But I have been carrying concealed since 1964, so I have no issues of familiarity or discomfort with a chambered round.
So, let's get back to basics; the need for training, drilling, and practice. Since you are uncomfortable carrying with a chambered round, the immediate need is for getting completely up to speed on safety procedures. These rules are intentionally redundant, in the hope that violating one rule will be offset by compliance with others, so that a potential disaster is avoided.
In my teaching, the one I most emphasized was keeping the finger off the trigger (and thus outside the trigger guard) until ready to shoot. This is a tough one when the adrenaline is pumping. Countless shooters have wounded themselves because they violated this rule when drawing. The natural inclination, when grasping a handgun, is to close the entire hand, but if the forefinger is on the trigger a discharge will result. This happens even when there is no stress, except perhaps from the clock. This habit can be trained out, and it is critical. If the trigger finger is alongside the slide when drawing, it can't close.
From there the student needs to be taught the fundamentals of shooting, including (among other things) target acquisition and trigger control, all the while being constantly reminded of the safety rules, and the need to always maintain presence of mind. These can be tough lessons, but they are necessary. This is the training element, because this is where the the most learning takes place.
Once the student has grasped these fundamentals, the next step is to practice them, thus reinforcing them, under the supervision and coaching of the trainer(s). This is the drilling element. But the student is still learning, because learning should never end.
The last step, which never ceases, is independent practice doing these same drills. Practice has to be accompanied by self-discipline. This is not recreational plinking; each shot must fired in pursuit of the objective of using the firearm in a defensive situation.
This can be a long road. The sooner you start the sooner you will get to your destination.