I wouldn't worry about it mate, everybody goes through it.
One thing I would say, is the IRT is
NOT as bad as you think it is going to be and how alot of people make it out to be. I had sleepness nights worrying about the course and the test, but, it is just a new set of skills you have learnt, and you will demonstrate them on test day.
On a personal level, I found that on test day, I was fully prepared for the test. On saying that, I must admit I was fairly lucky with a few things, in the respect that everything went to plan.
Instrument flying is quite demanding, however, I think the ease comes when you have that spare capacity to cope when things don't go to plan, for example, change to clearances, runway changes when anticipating a procedure, going around the hold again etc etc. Also, being ahead of the game and being ahead of the aeroplane helps a great deal. I did my IR before I became an instructor, but I am sure that your skills in flying will help you, in terms of freeing up that capacity. Are you instructing on MEP? If so, that will definately help you! When I started flying the twins, I must be honest, to begin with I found them demanding, but it was new to me, just like flying a C152 on your first PPL lesson. I am sure you can now fly a C152 in your sleep
.
In a nut shell, don't worry about it. You can only do your best, and I am sure that will be good enough. Which reminds me, I have my IR renewal next week
.
All the best.