I wish I would have had someone like you as a history teacher in school. Back then we got a very brief and basic "here are the definitions of socialism/communism. These may sound good, but that's just because you're young, they're actually bad. We're not discussing why, or going into specifics." I'm not sure the discussion even goes that far today in US schools, as most teachers like having a job.
Of course my gut reaction to this as a teen was to launch into my own "semi-tankie" anti-west, anti-imperialist phase. After a few swings back into liberalism, I eventually found a comfortable (if idealistic) ideological home somewhere between socialist democracy and social anarchism, but it was a long, bumpy, and confusing road there.
It seems quite a few on this site never made it past that angsty adolescent phase. They'll tell you "tankies" is an insult, or a slur even, but I'm not exactly worried about hurting someone's feelings with that when they openly call for authoritarianism and even support ethnic cleansing and genocides, as long as they're done by countries or groups that have their approval.