For months my phone was randomly turning on and off. One time this happened again (while I was reading something on safari) and the phone got stuck in a bootloop. I connected it to iTunes in DFU mode and it let me halfway solve the bootloop by attempting to update the iOS (Recommended by iTunes) . I saw my old lockscreen, filled out some setup info for the phone like wifi, apple id pass and other things and eventually it told me to slide to upgrade. I have tried to slide to upgrade many times but it always takes me back to the slide to upgrade page and I can't do anything else on my phone.

Other details:

iTunes says this phone has iOS 9.2.1

This phone has a passcode

This phone was jailbroken but a newer iOS may have put itself on my phone without my consent

The phone always used to randomly ask for my apple id pass and I had no idea what it was for. I gave it one time and it continued to ask.

What can I do to salvage my apps' progress on this phone or complete the updating process to break the loop? Should I try to apply a ipsw update file to my phone? iTunes will not let me backup the phone because it says it has not been set up yet but I am 100% sure my data is on this phone. I have even recovered the photos, videos and notes using Syncios but Syncios will not load up the apps even when I let it run overnight in no sleep mode on my pc. I'm looking for some type of 3rd party file explorer or backup program. Please answer if you have any idea of a program, service or other suggestion. Thank you so much.