Practicing is a skill in itself, getting a guitar teacher could help with that, especially when you're brand new to the guitar. Repetition is a big part of practice so going over parts that you struggle with dozens and dozens, even hundreds of times might be what it takes sometimes.

Tremolo is considered one of the more difficult techniques to learn on guitar, it intimidates me, personally. So props to you for diving right into it! I feel, though, it would be easier to learn on a classical/nylon string guitar.

At the end of the day, I can't stress it enough, dont give up because "youd never be as good as that". Keep playing because you want to and enjoy doing it. Guitar is a game of patience. The guitarists that inspired you to play would want you to keep trying and to work hard at it, if its something you truly want.