Thank you for your answers!

O I think I might not have explained it properly.

I DO go into sessions, only we don´t set up appointments in advance.

The way it works is, I call once or twice or so in a week and ask if she has an opening that day, due to a free appointment or cancellation.
When she does, she calls me back and I then jump into that appointment.

If there is nothing free, she doesn´t call me back.

Yes, well, the reason is, that suddenly I started to get very panicky when I had an appointment the next day and I could not sleep at all. And I mean, really not at all.

I thought talking about it in therapy would help, but it hasn´t so far.

I think it might be a burn-out thing because prior to this phenomenon , I´ve had many appointments in the week and I think maybe it got too much.