As a general viral immunology question (rather than seeking personal medical advice).
Would a blood transfusion from a COVID19 surviver to a sufferer be worth researching as a possible form of treatment? There is evidence in other animals (elephants) that blood transfusions are beneficial against viruses. BBC Chester zoo
More specifically would lymphocytes and other cells able to attack the virus from the donor outweigh the resulting increase in virus burden caused by adding the donors blood into the sufferer? and how does the is change over time from the time of the survivers recovery?
Needless to say this procedure risks crossing strains of COVID19 and other risks so would need thorough analysis of such risks before being practiced.