As can be read here, DSH2 means a fluency level of "C1", which means being able to read long complex texts, recognizing implicitly given meanings, speak fluently, etc. (There is only one better level, C2, roughly approaching a native speaker.) If you mistook 2 for being a grade, you have probably still some effort to invest, to reach DSH2.
I doubt that even two years are sufficient, if German was only one of many topics. Doing an intensive training, living in that country or similar for one year may suffice, if you have the right sort of mental disposition, are already fluent in a closely related language or similar positive circumstances.
See also this answer to a related question.