Frozen Galaxy Tab 3.7.0 with KK bootloader + twrp but detectable by usb help topic

I rooted my tablet a couple of weeks ago installed some compatible root apps and stuff and then my sister downloaded a game on the play store called Subway Surfers with a 93% of battery and then when the downloading percent is 36 my sister alert me that the device frozed and it was frozed just today and i try to connected to usb and then it detected it just frozed on the play store cant shut down the device and i dont want to reformat my device my mom just bought it a couple of years ago and i cant reformat it all those files are in there i cant backup the whole pls any other way it just froze to playstore plus if i plug it to usb the tablet do a sound and then my pc alerts SM-T210r before i root the device i ota update to kit kat 4.4.2 and then install twrp recovery and super su please help :(:(:(:(:(:(:(:(