The panic log you posted suggests there is a possible problem with USB connected devices. The main panic seems to have occurred with a Thunderbolt device. You are running Catalina 10.15.6. If you have not done so, then Download and Install the macOS Catalina 10.15.6 Supplemental Update.
I would begin by uninstalling BitDefender software. I would suggest taking these steps:
A Troubleshooting Procedure that may Fix Problems with macOS El Capitan or Later
You should try each, one at a time, then test to see if the problem is fixed before going on to the next.
If possible, backup your files before proceeding.
- Shutdown the computer and disconnect all third-party peripherals.
- Wait 30 seconds before you restart the computer.
- Resetting your Mac's PRAM and NVRAM
- Reset the System Management Controller (SMC)
- Reset your Startup Disk and Sound preferences, if needed, after resetting the PRAM.
- Test in safe mode to see if the problem persists, then restart normally. See How to use safe mode on your Mac.
- Repair the disk by booting from the Recovery HD. Immediately after the chime hold down the Command and R keys until the Utility Menu appears. Choose Disk Utility and click on the Continue button. Select the indented (usually, Macintosh HD) volume entry from the side list. Click on the First Aid button in the toolbar. Wait for the Done button to appear. Quit Disk Utility and return to the Utility Menu. Restart the computer from the Apple Menu.
- Create a New User Account Open Users & Groups preferences. Click on the lock icon and enter your Admin password when prompted. On the left under Current User click on the Add [+] button under Login Options. Setup a new Admin user account. Upon completion log out of your current account then log into the new account. If your problems cease, then consider switching to the new account and transferring your files to it - Transferring files from one User Account to another.