@orchid2 I understand and sympathise regarding the panicky feeling and anxiousness regarding chemo sessions.
It might be worth talking to your oncologist or GP about prescribing some anxiety medication?
I was extremely concerned about nausea and vomiting before my first chemo, so much so that my oncologist prescribed me a single dose of Lorazepam 500mg (I think they were concerned that I would work myself up into such a state that they wouldn’t be able to get me in the chair lol 
)
I had to take the Lorazepam tablet before I left home on the day of chemo, just to relax me. It did help. They were happy to prescribe it for me to take before every chemo session but I found I didn’t need it after that first session, once I knew what to expect and trust the the anti sickness meds were going to work ok for me. But they would have continued to prescribe it if that had been my choice.
From the NHS website:
Lorazepam belongs to a group of medicines called benzodiazepines.
It’s used to treat anxiety and sleeping problems that are related to anxiety.
It can also be taken to help you relax before an operation or other medical or dental treatment. This is known as a pre-med.
It’s thought to work by increasing the levels of a calming chemical in your brain called gamma-aminobutyric acid (GABA).
Lorazepam is available on prescription only. It comes as tablets and as a liquid that you swallow.
Or they might be able to prescribe you some sort of different anti anxiety medication that you take more regularly or in the few days leading up to your next session? It might be worth a conversation with them?
Hope you manage to make the right decision for you x