If you are are still experiencing difficulties with your device even after 5 factory resets, I would suggest your reinstall your firmware again. Just download it from your manufacturer website and install, be sure to back up your personal files.
During installation follow instructions carefully to avoid bricking your device.
After reinstalling firmware, restore your user data. You can re-root if needed.
As for how to install the firmware without a PC:
You have to unzip the firmware file if not already unzipped, then extract it to root of sd card directory. Now switch off the device. Press both volume buttons together with power button SIMULTANEOUSLY, and you should boot into recovery mode choose upgrade then scroll down/up to the firmware file. Wait until it finishes installation. It will reboot automatically, you may wish to wipe cache partition before restoring user files from backup.
Note: in some Android models it automatically detects firmware files such that you don't need to press the buttons earlier, but check if this works then try using first method. In addition you need to remove your sd card, just after it finishes firmware installation to avoid repeating the upgrade.