Thanks all of you so much for all the replies. It does really help to hear that some of you were where I am now and understand (and got better).
I took some codeine this morning, which slightly took the edge off the pain and calmed me down and I had a bit of a snooze. Pain is worse again now but I can cope at the moment distracting myself with reading and watching stuff. Have been in bed all day and it's marginally more comfy than sitting. Obviously codeine is constipating as well so don't want to take too much of it but it's there if things get unbearable again.
I also tried some frozen peas wrapped in a towel last night, which was, er, different. A different sort of pain anyway. Might try a coldish shallow bath with either Hydromol or Epaderm. Has anyone tried those oat sachet things you can get for the bath?
I may try restarting Betnovate. I know most doctors are very wary of it but I don't think it can make this any worse?
Unfortunately the gynae is away this week but she is back next week.
Panda I am not sure about the deso. I've been on single deso since Jan 2021 (and double for about 5 months) and the atrophy was diagnosed end of June 2022 so probably isn't the cause but then the atrophy didn't happen overnight so who knows.