Hey, so i set my goals...but how to reach them?

I played guitar for 3 years, 2 years classical and one year eletric. I´m into lots of different music styles, but mainly metal. My favourite bands are metallica, lamb of god and nirvana, but I like stuff like Rodrigo y Gabriela, taylor swift, jack Johnson, paul gilbert, jeff loomis, children of bodom, soil and stuff like that, too. I´m more interested towards rhythm guitar, my favourite guitarist is james hetfield. I would like to learn some grooving metal with flamenco flavour and some nice cleans (like battery by metallica, or grace by lamb of god)

My goals are to be able to play ten songs of lamb of god and ten songs of metallica (the rhythm parts), but I don´t know where to start. I know countless riffs of both bands, but only one full song. I would like you to give me some advice or some kind of list of songs to gradually increase my skills.

My playing level is advanced beginner. I learnt enter sandman (rhythm parts) all the way through in a few days last week, I can do half of the nirvana unplugged songs, I can do the clean parts of the day that never comes, I can do the first half of metallicas cyanide, I can do seek and destroy without the fast part, I learnt lamb of gods set to fail all the way through up to 80%, that’s all rhythmparts.
Solowise I can do sweet child o mine to the first sixteenth note run in the 3rd solo.( I can do more stuff, but that’s the hardest)

My main problem is I practiced a riff, for example the hourglass intro or the master of puppets intro or the intro of redneck for weeks, but I didn´t get it, but stuff like seek and destroy was done in a week (half year ago). I have a teacher, but he helps me with soloing, and that’s great, but he doesn´t like metal that much. For technique stuff I got rock discipline, but I often use only the warm ups

I hope you can give me advice, or a list from easy to difficult songs to work through, thanx in advance (and I´m german, sorry for bad English)
MT's only "suggest me a song" thread is the place to go for song suggestions

Your English is fine, by the way.

Different songs will proove harder or easier than others. With patience I belive you can achieve almost any level of difficulty. Practicing with a metrone is a good idea, it means you can slow down the speed you play the song until it is locked into your muscle memory. Then you can slowly increase the speed until you eventually reach the target speed. Just don't increase the speed until you can play the part accurately at the slower speed.

Maybe look for a new teacher who teaches whar you want to learn
^that. And always ensure that you don't lose knowledge of what you've accomplished ie classical guitar, theory, etc.