You are not alone in this situation. I live overseas, and my father in the UK, who lives alone since mum died, is disabled and also had a stroke. He just about manages to cope on his own, but he's very lonely whilst in lockdown, and has no one at home to even talk to, except the odd phone/video call. At least your parents have each other. I'm gutted that there's nothing I can do to make things easier for him under the current circumstances.
My daughter in the UK was planning to visit us and now she can't, so I have no idea when we'll get see her again. And my son, Dil, and GC, who live in another country, not too far from us, who we normally get to visit every few weeks, we've not seen since December, and no idea when we will get to see them again. Our GC has changed so much during the past few months, we feel we are missing out on so much, but there's nothing we can do about it.
The important thing is that we all need to stay safe. I could not live with myself if I decided to break the rules, and infected one of my loved ones, just because of my longing to see them.