I had two lots of antibiotics after swollen legs and feet, not after Covid but after my first jab. I was very worried about one toe in particular, which I think was bitten by a nasty insect we have here in Dorset, the Blandford Fly. I was feeling so ill I wasn't paying attention to very much at all at the time.
When things began to look bad after a few days beyond the last course of antibiotics I used my knowledge of plant based medicines - my father's mother's family were herbalists, midwives and nurses. I sent off for some ginkgo biloba tablets - it is an extract from the maidenhair tree, and a circulation booster. Much to my relief I saw improvement almost at once and in a few days the skin peeled off one toe, the black nail came off the one next to it, and it seemed that things were getting back to normal. So far - even after a second jab, no further problems.