I recently tested positive for covid-19, ive completed my isolation period and feel perfectly well again, however ive developed a sore spot on my neck, it feels like my thyroid gland is swollen on the right hand side.

Thyroid : You should see a doctor in person. Thyroid function can be affected by illness. Is it possible that you have a knot in a neck muscle?

Need to examine: It is not feasible to provide a meaningful opinion without additional history, physical examination and may be some tests. It would be prudent to see your doctor. Have a healthy diet, exercise 30 minutes/day, drink plenty of water, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Wish you good health!