After reviewing similar posts, I think I may have just fried the board, but I wanted to post something just in case there's a way to save the board.
I plugged the board in using Vin with a 5V external power supply (I'm assuming this is where I made the mistake). After this, I smelled a bit of smoke so I unplugged everything. Reconnected the board just using a USB to my laptop, and then I noticed that the CHRG LED was flashing rapidly and the board wasn't being detected on any of the COM ports. The LED flashing and the board not connecting happened once earlier in the day but resolved itself shortly after. This second time has persisted however.
I read other forum posts and tried double-tapping the reset button to enter bootloader mode, and the flashing on CHRG does stop, but the 'L' light above 5V doesn't turn on and the board still isn't discoverable, so I'm assuming it didn't work. If I unplug the board and plug it in again, the flashing on CHRG returns.
I checked my COM ports manually in my computer and it shows the COM3 which my board is usually on as grayed out. When I tap on the port it says the COM is undetected and can be fixed by plugging the USB back in, but the board has been plugged in the whole time.
Another odd detail is that if I plug the board in through Vin with 3.3V, the flashing doesn't occur, but if I plug it into my laptop it starts again and still can't be found.
If there's any chance my board isn't fried and I don't have to buy a new one, please let me know.
Thanks for any help anyone can provide