If you've been a shielder, I think it is too early to think of travelling abroad. I can understand why you want to go but it would be better to have the rest of a long life to enjoy your family rather than to jump too soon and find they are living a life without you. It is hard for you but being sensible at this stage may be a life saver.
To think that London, or anywhere else for that matter, does not belong to any one demographic