Productive language problems - caused by mental illness?

Hi, everyone. I've been experiencing something strange lately and I wanted to ask you your opinion.

Lately, when my mental health worsens, it becomes harder for me to use English productively. I can listen to or read something in English and I understand it as normally, but I struggle to write or speak. Right now, I'm struggling to write these sentences. It's as if my level of English had dropped along with my state of mental health. This had never happened before, not even at my lowest points in the past. Even if the final version I post seems perfectly normal, it has taken me way more time than it would normally. You have no idea how many times I've erased entire sentences I had just written, paused to structure the rest of the sentence I was writing, or had to correct weird typos. I haven't hurt my head recently, so physical brain damage isn't the cause of this.

I should note that I'm not a native English speaker, although normally I'm fluent at a C1 level (at college we sit language exams following the CEFR and they tell us what level they are).

It's taken me lots of effort to reach out to you. I have wanted to do some other times, but I have never dared.

Do you have any thoughts on what is happening to me? Has it ever happened to you? Do you have any ideas on what I could do?

Even if you cannot answer any of those questions, it will be enough for me to know you've read this, that I am not alone. Thank you for reading.