My phone has been lagging, locking up and randomly restarting or just freezing. I have factory reseted my phone multiple times and it still will randomly lag out. A few times it randomly freezes, then shows a blue screen that says something about a custom os system press up to continue and down to restart. It's annoying because anytime I try to do anything it just freezes some times I have to hold the volume up+down+power to get it to turn off or back on. I can't afford to get a new phone... what can I do?