Do you phone them? Not every day, as you phone your mother, but at whatever intervals seem both to suit you, and are not obviously interrupting their day/evening. Not to criticise them for not phoning you either, but just to tell them you are recovering from the Covid but still feel tired, to chat, pass on any news, ask whether they have done anything interesting, and so on. And not a long conversation - set a timer if necessary, and when it rings, say "Sorry, I have to go. That is the oven calling me." Leave them knowing that you have been in contact but that you aren't being the same as your mother. They probably know exactly how demanding she is and are hoping you don't go the same way, but there is nothing wrong with contacting them with a "progress report"
The phone works in both directions.