I have been waiting for an ESA Assessment for 1 year now. I was told about a non-profit organisation, Fight Back 4 Justice, which provides an advocacy service to support people through the applications and appeals for PIP, DLA, ESA, UC claims and appeals. You can see the support they offer via this link fightback4justice.co.uk/cho...
It cost max £11.99 per month. You only need to pay one month membership at a time. Maximum 2 if you need help in filling in the form, Assessment prep advice and support writing an appeal if your claim isn't upheld.