You have been unlucky. Most assessments have been carried out on the telephone. I don't think they have done any home assessments since the pandemic ended.
You have two options: 1. Ring the assessment service and ask them to change your assessment type to a telephone assessment, saying you are housebound.
2. Get a letter from your doctor saying that a face-to-face assessment would cause you "Overwhelming Psychological Distress" and then contact the assessment service and ask them to change your assessment type and tell them you have a letter that you can forward to them.
Whether you take option one or two - the assessment service can refuse, in which case you appeal again. You can only appeal twice.
Be aware they have no legal obligation to give you the assessment type you want.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems