It's impossible to explain yourself when someone "blocks" you.
It sounds like it was a very confusing relationship, for sure. I think I would have also taken a step back in order to sort things out.
I am sorry you have not been given a chance to fully express yourself.
I wonder why you are feeling panic?
Does this situation remind you of anyone else in your life?
Have there been other situations where you were feeling very vulnerable and were not allowed to explain yourself completely?
Do you see a therapist?
I hope you can get over the panic. Panic is such a horrible feeling!
Have you tried any deep breathing exercises to interrupt the panic?
There are lots of them on youtube.
You may find additional support in the relationships and Communication Forum as well.
Please take extra good care of yourself.

WC