Cornwall's not going anywhere, Mummypig. Yes, it's a bit shit at the moment because there are so many unknowns but the way I see it is that every day we built up micro exposures to the virus and, because most of us are staying at home, we do this at safe levels. When we go out, we do so infrequently and follow the rules, therefore keeping our levels safe. We do, most people do and the virus doesn't mean death en bloc.
I query the figures that are quoted because they're snapshots extrapolated to make a point rather than raw data which gives the whole (massive) picture.
The way I see it is the 2020 is a bit of a 'lost year' but we'll still be able to do some things, slowwwwly at first. I don't know about Cornwall in July but, perhaps September might be possible? Or you'll go somewhere else beautiful?
Can you skype your Dad for now? To be honest, I've seen so many people flout the shopping-for-vulnerable-parent rule by picking up bread or milk and calling at parents, only to drop the food outside and wave madly, chatting through the window but, perhaps that's an option?
In the meantime, just find some things each day that make you happy, whatever they are. For me, it's get at least an hour of quiet time just for me - and get my exercise in every day, it makes me feel better and stops me putting weight on.
What do enjoy doing that you can still do?