Medical documentation issue

Hello all,

I've been an RN for 22 years, and until now have never violated the rule of altering a document by writing over. Well, I did it this week....I'm aghast and shocked that to do such a thing would ever cross my mind!! It was on 2 injections that I gave in the past 2 months (1 every 4 weeks). I saw that I had written I had given half of the dose ordered per the Dr., and without thinking, wrote over my handwriting to reflect the full dose. The next day I was terminated for doing this. Some background; I hated the job I was at, and was overwhelmed and unsupported by everyone I worked with. Anything I did was never enough, and never correct....I had a total hysterectomy this past April, returned to work June, and went thru complete menopause due to not being able to take HRT. I realized my thoughts and feelings weren't like they used to be, and the daily anxiety of simply going to work put me into a near panic. No harm came to the patient, but I was clearly wrong in what I did. I can't even explain why in the world I would do such a thing...please give me feed-back on the possible repurcussions of this action. My husband told me he was glad I was out of that place, but I'm worried sick about my liscense. I've never ever done anything like this before!!! Please help me assess what I need to do. I live in Michigan. Thanks in advance.