Post COVID effects. All these symptoms.!

My dad was tested positive for Covid 1 month back. After usage of anti inflammatory drugs such as Deflazacort 6mg, Clarinova and Clarithromycin medicines, infection was completely cured within 10 days. However, my father became weak and developed another symptoms such as blood motions, Muscle cramps and digestion problems. Since, 2 weeks we have been using medicines for these symptoms and these got cured. Later after the dosage.. my father again started to develop these symptoms. Yesterday we have checked his blood pressure which is of 171/99 which is infact higher than usual. Currently he's feeling little pain at the backside of his body behind the heart and that pain (cramping kind) occurs only when he does work with his left body. He still has gastric issues. As BP is high, I am little panicked about the symptoms.. kindly suggest what needs to be done now and the reason for occurrence of all these symptoms..!!