I only listened to the first few minutes of Hollowed be Thy Name. You need to take a step back, stop trying to sing the most difficult songs (Maiden, ect.), get a coach / teacher / some form of lessons. Your pitch is way way off. Like you sang the song in a whole different key (or several different keys) . Start with the basics with a good coach and get your pitch fixed, learn how to breath, and all that. There are several coaches in here that can help you. Robert Lunte, Dan Formica, Kevin Richards, to name a few. Grab one of them. The more you sing with the mistakes you are making, the longer it will take to fix them, as singing depends in muscle memory, among other things.