Fix my website

The wordpress backend of my website is not functioning correctly. It has previously been working fine but a prospective customer alerted me to the problems. The menus for editing some options is blank within the wordpress backend where it used to appear and I could enter or select the options.. Also my quotation form is not complete and I cannot edit the options for this The theme I am using is poor and is not supported by the original developer. I am assuming that my wordpress auto upgraded or something and the theme is no lnoger compatible, but I would like these issues resolved where possible. A list of the major problems are: 1. Cannot submit the form because of mandatory fields with no content 2. I cannot edit or set the mandatory parameters whereas before it was fine. I need to be able to edit the options within the removals tab on the wordpress backend. I also need to be able to edit the form to inout United Kingdom as a country option, Yes or no as options for the elevator drop downs, and also submit the form successfully. I must stress that these options were available previously within the panel when you select the Removals Options tab, but I don't know why they are currently not appearing. I am sure that if you get the panel back up it then I can do the rest.