Sorry to hear this bud :(
My mum is in remission from leukaemia so also at-risk. Somewhat luckily(?) I seem to have been struck down with very mild symptoms so am in self-quarantine for 14 days. The good thing about this is that after 14 days of not having any contact with anyone I'll feel safe and able to visit her without risk of infection.
Far from ideal for most but worth bearing in mind? I'd be very hesitant to visit anyone in the at-risk categories without having been in isolation for 7/14 days beforehand.