Hello Anja,
I hope you end up going on your vacation. Once you're there you can soak up some sunshine and relax.

I know there are other people who post here who have travelled by plane so hopefully they can give advise. The car trip sounds very long and tedious unless you could do it in stages by staying overnight in a couple of places on the journey.

It's still April, so it would be a shame to cancel now when you may be feeling so much better by August.