thx now backup for my data partition works!Why would you think that you would keep TWRP after flashing stock recovery? Also, why would you flash stock recovery after flashing TWRP and SuperSU? You either have TWRP or stock recovery, not both. Also, don't ever recommend flashing stock recovery after modifying system in any way unless you reflash whole stock system as stock. Anyways, all you need to do to get TWRP back is use the :
fastboot flash recovery TWRP.img
Earlier my internal storage was 0 Mb and also data partition. Why? thx