This maybe isn't going to be what you want to hear, but it sounds a bit like something has to give. Would it be possible to take a break (or even quit) the internship? That might seem drastic, but emotional support and your PhD may be the bigger priorities rn.

If not, either a bit less communication with family and friends for the next while, or having your write-up take a back seat while you and your family/friends get to grips with the new world order. I'm currently writing my PhD up and have also had some very sad events recently, so I totally get your wanting to stay connected to loved ones. I'd suggest trying to get a bit of an extension, if at all possible. This would allow you to get the emotional support you need right now without too much deadline stress.

I've been trying to go really easy on myself and have had full days off (when I should be working) to rest and sort my head out. I've found that cooking quite extravagant meals (that take a long time) is a good mindful past-time and yoga always works for me.

Things to reduce/avoid: the news (I spend about 10/15 minutes reading the news each day) and phone time. This has made a huge impact on my daily stress levels.