Am I losing it?

It's happening again. Here I was working with uninterrupted focus on my job and just when I thought I was about to reach professional success, I was hit like a freight train by my audit scores. They were low, and that's not all, they're now becoming a pattern. It's been 3 weeks now since I dropped down from my usual 85 above score(or even 100) to a new low of 50. That truly sucks. I was told to pull up my socks by my team leader. 

I am able to identify certain thought patterns from a similar experience in the past, where no matter how much effort I put in my work, it was still not enough and I was later sacked by the company, which I will not name here. This happens every time I'm being sincere about my work. Is this going to resolve itself with time? I don't know but I believe that's highly likely. If my performance doesn't improve soon I'll be at a risk of being sacked again. I've already started considering alternate career options, whether or not I will work in the future in the same domain I'm not entirely sure but it's going to be IT related for sure!