Am I being too hard on myself

I am three weeks from completing an LPN program and up until a few days ago was really excited about completing it. The reason I’ve been so anxious and depressed the past few days is because at clinical when I was doing charting for orthostatic hypotension on a patient I hadn’t gotten the patients heart rate and I was the last student to be done charting and my instructor can be rather harsh at times I didn’t want to admit that I hadn’t gotten the patients heart rate so I just put some values in the chart. I felt really guilty about it later thinking how I was falsifying medical records that I went back into the chart and updated it by typing after the false numbers, “error, did not obtain”. Do I have a reason to feel horrible about this or should i just move on. I know I will never do something like this,again and have felt because of this doubts about whether I even deserve to be a nurse. I also feel guilty because my instructor doesnt know what i did and will give me a grade based on my performance and I have doubts about whether I deserve a good grade on the clinical because of this. If she knew what i had done, well im not sure what she would do and maybe id get kicked out of tbe program. I don’t know what would happen. Do I tell my instructor what happened or would that be unnecessary. Please give me some guidance about this.