Rattling behind/under driver seat in 2009 Corolla

Hello, I recently got my late uncles 2009 corolla. Idk how he ran it but I've had it for the past 15,000 miles and take pretty good care of it. It's ran fine for past few months; however, this weekend I took a day trip and now my car makes a rattling that can be felt on the floor of the car behind the driver seat. On the trip I hit a pretty deep pothole on the driver side but it didn't start until after I had blown the passenger rear tire on the freeway. I don't know which of these events caused it, if either did. I don't really know what part it could be.

For more info, the rattling doesn't occur when I'm on the freeway but it is pretty constant on the street. I've taken photos of the underside but there's nothing that can really signify what it is. I can upload them if they would be useful. If I can get any help on this I'd really appreciate it.