I remember being in 10th grade just sitting in my room---in total rage.
There comes a point in your guitar playing career where you will limber up your fingers to the point of assimilating a wide breath of guitar styles and licks in relatively short time--even if you've never played licks in that style before.
Yet, as you probably have already guessed, before that point all you should do is 1)Practice the licks over and over again in a tempo that is comfortable for you. Comfortable means you can execute the lick in time and with clear articulation at least 12 times in a row without rest. 2)RELAX!!! Shredding--the right way like a virtuoso--is a skill that takes a long time to acquire. You will just have to be patient and woodshed. Take comfort in the fact that all those guys you admire were once in your shoes. Every single one of them.
3)SOLVE PROBLEMS. Pay close attention to what you play and what you feel when you play it. If you are not consciously aware of moving every single finger independent of all your other fingers, then you need to dial back the tempo further. Look at how you hold the pick---if you are using your fingers or elbow to help or assist in picking, dial down the tempo or start using just your wrist to pick. ((There are a lot of debates about this, but the reason for using the wrist is that it lends itself to an almost effortless motion that you will be thankful for later when it comes time to tackle passages at 200 bpm))
Back In Black isn't a song. It's a divine call that gets channeled through five righteous dudes every thousand years or so. That's why dragons and sea monsters don't exist anymore.