I started having PVCs and tachycardia after covid. Exact same treatment that you were prescribed. So far, Cleveland clinic has not found an intervention that is effective. I am seeing an electro physiologist to look at a corrective procedure. I am not suggesting that is the route you need to go, but I had no cardiac symptoms prior to covid. There are a couple more medications that are strictly for tachycardia/ PVCs/ PACS. Speak to your cardiologist again and maybe ask about different medications. Calcium channel blockers are decent but your body does take time to adjust.