Hi Chloe, just sending you my encouragement. As the mods say, tell it like it is, watering down your extremely disabling problems is a form of untruth in itself, and won't help anyway.
Did you get hold of a PA4 assessor's report, from them after your assessment, or was it a paper assessment? If you didn't ask for one you can still do so.
BIS's suggestion to put that you believe they have confused you with another claimant is genius, I'd give it a go.
Thinking of you,
best,
Denby