The funny thing for me when i was in school was that i was constantly frustrated and did similar things(ruining pieces that were almost done),but now years later,for me, i find that i really got alot more out of those classes than i couldve imagined then.Try your best to really take in all thats goin on. I miss school and occasionally go sit in on figure drawing classes to just be around other artists/students and to try to still take in the things people have to say and teach.