I feel your pain, I cycled 6 days a week. But 15 mo. Of long Covid, I am happy to cycle an half an hour a few times now. The key is slowly working your body back. I was told by Covid recovery clinic have to pace yourself, start with 15 mins 3 days a week of physical activity for 2 week then increase to 20mins. For 2 more weeks etc. It is very hard to do when you are use to pushing yourself physically. Take daily naps too. And listen to your body, some days you just have to rest. Hang in there you are not alone. Notice things that make you smile, write them down and look at list when you have a bad day.