The righht turn arrow is in a narrow lane together with an outline of a bicycle. Your GSV view shows two signs, one each side of the road, with a sign below saying "except cycles". So your task is to be able to convince an adjudicator at London Tribunals whether the signage is adequate of not. In addition, you could add in your BB badge issued for mental health, and expand on what that is all about, but the assumption is if you can drive, then you are competent to react to traffic signs, i.e. your BB is not a Get-out-of-Jail-Free card.
At the moment, I'm struggling to think of a robust appeal argument but wait a bit as someone else may have a suggestion. You could look at the Equalities Act 2010 for guidance: -
https://www.legislation.gov.uk/ukpga/2010/15/contents
