Alex,
With the NHS you have the choice to go to any Hospital you choose, at any Trust. If you feel you are being given sub-par treatment by anyone call that Hospital, or NHS111 (this is for UK), and ask to speak to the PALS (Patient Advice and Liason) Office. You can talk through your concerns, or put in a formal complaint.
Don't let your age put you off, and don't stop fighting for an answer to the cause of your condition. Above all, don't get depressed - come here and rage against an unjust World - there is always someone to listen.
Don't forget to get your bloods and B12 levels checked as MrsD advises.

Dave.