Slightly different circumstances, but I'm a bit younger than you and frequently housebound and on my own a lot due to a disability.
It was really hard and I needed to grieve but I'm generally ok now. Hobbies have made a huge difference. The biggest for me has been learning to play new instruments. I learn with a tutor who has a social group where the adults can meet up over coffee and cake every month and show the pieces they've been working on. When I'm well I also do Open Mic nights (or just listen) and there's a really strong community which has come out of that.
Other friends in your situation have joined choirs or am-dram grouos which are very social or learned to paint/knit/crochet and joined groups where they work on their pieces together.
I've definitely had times when the thought of getting out to do things hasn't just been physically impossible but mentally overwhelming and emotionally distressing.
With Music (or crochet or painting or whatever floats your boat), what was good was that I could start learning off Youtube, in my PJs and stop/start whenever I felt like it. Sometimes that involved a good cry, but no one saw and when things improved I could take the hobby out of the house and meet other people through it.
Some days I can walk, some days I can't but I find walking and being in nature helps me to regulate my emotions. I'll listen to music or podcasts (which makes me feel less alone) at the same time. Sometimes, leaving the house is too much for me, so I've bought a walking pad which fits under the bed and I put it somewhere with a nice view and walk and listen to audiobooks, usually autobiographies of inspirational people who have overcome similar hardships. Again, it helps me feel less alone.
Exercise is really good at shifting your emotional state and boosting your mood, if you can manage it, do. It WILL feel awful at first, but I just committed to ten mins at a time and eventually I realised how much better it always makes me feel. There are lots of amazing videos and instructors on Youtube.
Also therapy, EFT, poly vagal exercises have all really helped me deal with the big emotions and grief.
It will get better, I promise. This phase is awful but in time you'll feel whole and happy in your own company and that in itself is such a gift. You can still create a lovely life for yourself with this time and space that currently feels like a curse. You really might surprise yourself.