If you find travelling alone difficult or stressful then there are ways that you can access support to do this. National Mencap have a page on the ‘advice and support’ section of their website mencap.org.uk where you can find out about the law, as well as different ways to be supported on transport.
Living on an island means that if you want to get anywhere you will most likely need to travel by boat. Wightlink will offer to support a person with a disability and in some cases carers can travel for free. To arrange support you are expected to contact the ferry companies at least 48 hours before you plan to travel. You can find out more by looking at the FAQ section of their website.