I Had A Full Knee Replacement. Ive Had 4 Procedures

I had a full knee replacement. Ive had 4 procedures on this knee since Dec. ive had 12 surgeries in 5 years from my back, my sinuses, my knees, etc. i do have hypertension. I’m on meds. After my surgery, getting home, I passed out, my bp dropped so low and it happened again 2 weeks later. Now my bp is high, higher than its ever been. Yes, I’m overweight and plan on working on this now that I can walk again. My cardiologist has given me more meds. This morning, my bp was a little high but my heart feels like its beating really fast. Could it be anxiety or what? Ive had all kinds of tests but have been told my heart is fine.