What are our rights? Renting property riddled with damp and other issues?

There are many legal issues involved here. Landlords have a duty of care too their tenants as do tenants, have to realise their responsibilities within the criteria stipulated in their leases. I would advise that you go and see your doctor in-re your illness and then make an appointment with either your local housing officer or citizens advice councillor! Also make note of the date and time of all correspondence including telephone calls with your landlord and bring this information with you to any meeting!