Struggling with feeling abandoned

So fear of abandonment is a big trigger for me and I know I haven’t actually been abandoned but it still feels like it.

I see my t weekly and last week she was on holiday. I find breaks hard but a week is ok and especially as planned in advance. Then on the day I was due to see her she was ill, so that got cancelled and then the next week I can’t make. So I won’t have seen her for 3 weeks in row. I’m upset because that last week she had always said it could be re-arranged and we’d sort nearer the time. Now, however she has no other appointments available.
It has taken me ages to open up and before the break I felt like I was really making progress and starting to be more open and my life in general was getting better and more stable.
After she cancelled the appointment this week and knowing I won’t see her next week I feel really abandoned. And I’m really worried that I’ll be really distant at the next appointment as I won’t feel safe I guess. I’ve started self-harming and other destructive behaviour that I’ve not done for months. I’m really struggling and I don’t know what to do. I also feel ashamed that I’m so obviously dependant on a therapist and I don’t think she’ll understand any of this.
Just a rant really but any advice appreciated.

I am sorry to hear about this long unexpected break and how upsetting it has been. Have you thought about talking about these feelings when you see her again? She might understand more than you think. It's really common to struggle with breaks and to feel abandoned during them even when your brain knows that isn't what is happening. If you don't feel safe at your next session, it's okay to say that and see what she says.

Therapy is tough, and it is brave to hang in there and try to find your way through these uncomfortable feelings.