Stress worsened by work

CW: SH ideation

I'm currently 7 months into my first full-time job that isn't seasonal. Last week my department head came to me with a "performance improvement plan." I know there are a few things I can work on and improve without too much effort. The main issue is me having too much free time, for which my D.H. needs to delegate things to me more (which she acknowledged).

Now, all these little things feel so... well, small. They don't feel like things I should make a big deal about. Yet the feeling of confrontation (even if mild) and knowing I'm failing at something (even if they're small and this is my first real job) makes me feel like freaking trash. After my D.H. left me with a paper outlining the problems, I was so anxious and stressed and overwhelmed on the way home from work I had to actively remind myself to not veer my car into oncoming traffic. I've never been willing to label these types of thoughts as SH, but thinking of seeing my D.H. tomorrow and acknowledging these things makes me want to do something very stupid to myself.

And unfortunately, my therapist is not available this week. Its not like I planned to feel so volatile, but honestly I feel unstable right now. And knowing the source of this mood shift is something that on paper is very small just makes me feel like an even worse person. Like, there are people with objectively harder lives, and I want to do something bad to myself because of a little criticism? The same brain that makes me act like this is actively shaming me for the same reason.

I don't know what I'm asking for. I don't know what would fix it. I just feel bad and feel even worse for feeling bad in the first place.