Lagging on my iPhone12

I purchased my iPhone12 about 2 months back. Initially it was running very smooth and fast. Lately, the phone has become very laggy, the frame rates drop to extremely low while using and games have become unplayable. The screen freezes at moments and becomes unresponsive multiple times during the day. This started happening after installing iOS 14.2. Same condition of my iPhone after update 14.3. I don't know if this is due to the iOS update or due to any other reason. Please help. Any suggestions that can solve this issue?