There is a chance, albeit small that the wallet was not overwritten when you formatted your phone, you might be able to use a data recovery program (e.g Recuva) to retrieve the old wallet file.
For now, stop using the phone as the more you use it, the higher the chance it gets overwritten.
I'd say casually. I don't do something crazy with my phone. Phone calls and surfing on the web when need be & listen to music. That's about it I think.
Thank you for the info! How would I proceed to use Recuva on my phone?
You could just take the SD card out of the phone, and use Recuva on your computer to try and recover the files. This will likely be quicker as recovery processes with a deep scan can take hours depending on the side of the card. Just make sure you demount the card properly to avoid corruption and give the best chance of recovering any files which may be on there.
I succeeded to make it work on my SD card but not on my internal storage. When I choose the internal storage option on Android, the drive doesn't appear on Recuva. Whereas if I choose mass storage (only external) it appears.
I'm trying to recover the SD card first because I'm not entirely sure whether the backup was saved on internal or SD.
Edit: not on the SD card. Checked all the files. Now how do I get it to recognize my internal slot?
You'll need to enable mass storage on the device, this should be available in settings if you're using android. I'm not sure if it's possible on iOS.
Mass storage mode (MSC) is only for the SD card. I've used it to recover deleted files on it. As for the internal card, I have to use debugging mode which I turned it on and use the "transfer files" (MTP) but the phone doesn't show up in Recuva for some reason
https://android.gadgethacks.com/how-to/use-your-android-phone-as-wireless-flash-drive-for-windows-mac-0174599/
If that doesn't work, try fonepaw instead, this appears to be specifically designed for Android recovery.