honestly mental hospitals are not nice places to be, you certainly shouldn't wish to be in one... I agree with what others have said that if you're struggling with health anxiety etc being in a hospital is not what you need, you need distance from medical places in general and unfortunately an IP unit is not going to offer you anything special that an OP therapist cannot give... inpatient is used when a person is a serious risk to themselves or others, so as a last resort to keep that person alive until their illness can be managed... what you need to do is challenge your anxiety and so on, which you can do more effectively outside a hospital setting
I do think the NHS fails in terms of mental health care in some respects but I think it is a good thing that they do not admit people to hospital easily, I don't think admissions to mental health units are helpful if they can possibly be avoided