Reboot loop

[Mizuhashi]

so i downloaded an app yesterday in app store's editor's choice apps, i tried fleksy keyboard since it can send gifs etc. (my phone's sim card slot is empty at this time)

the next day, i wanted to reinsert my sim card. after restarting the phone, it automatically reboots after the lockscreen shows up for about 2-3 secs (and sometimes it doesnt even reach the lockscreen and just restart after taking a long time loading in that purple screen).

when i managed to unlock my phone in that interval, i see all my widgets are giving errors messages and there's an app crash notification which says 

''Fleksy has crashed'' and i cant press the OK or REPORT button.

i did some research and found out that the phone can be fixed by entering safe mode and delete the app. i've tried various ways to enter safe mode and all of them failed.

- i tried to enter safemode by rebooting from long pressing the turn off button in that 2-3 secs interval and select the reboot in safemode option. 

- i tried holding the volume down button and turn the phone on and it fails as well.

- i tried turning on the phone and when the sony logo came i press volume down and was supposed to hold it until the lockscreen shows up (but when i try this method, the phone doesnt even reach the lockscreen and rebooted before it even shows up)

So i'm pretty desperate right now since i got a lot important files that i haven't backup inside the internal storage. any advice is worth to try. i dont want to reset my phone to factory settings by using Sony PC companion repair function since it will format the storage.

any help is welcome. Thanks

**UPDATE:

now everytime i try to turn it on, it doesnt even reach the lockscreen anymore. it reboots itself after a long loading time in the purple screen

[Phy]

Take out the sim card and sd card and boot on safe mode. If that doesn't work repair it with Sony PC Companion, but it will delete everything.

[Phy]

Contact Sony Xperia Support.
http://support.sonymobile.com/global-en/contactUs/

[Mizuhashi]

dear phy, thank you for your reply

i already took everything out.

i'll use PC companion as a last resort, for now i'm looking any other solutions that doesnt involves memory lost.

[Phy]

I believe Thommo suggested to use flashtool and exclude the data.

[Phy · Accepted solution]

And uliwooly has a guide on how to use the flashtool.

/t5/Xperia-Z2/How-to-manually-update-downgrade-root-2014-Xperias/td-p/593459

[Mizuhashi]

i dont know anything about flashtool, since i never intended to root my phone.

please explain to me more about flashtool and what are the consequences. exclude the data ? do i root my phone without afecting the data in it?

thank you for your reply

[Uliwooly]

@Mizuhashi

You are not going to root the phone, you are going to flash it. 

[Mizuhashi]

@uliwooly

so, i won't lose any data in my internal storage? since it's full .. 

[komilAD]

You won't lose data if you untick wipe data in flashtool. But mostly it is recommended to wipe everything when flashing roms. BTW you still requires a ftf file to flash. So i recommend xperifirm to download.