I am a student in Germany and i have a residence permit here for 2 years, which is also a Schengen visa, I suppose. Do I need a separate visa if i wish to travel to Romania?
No you do not need a separate visa to visit Romania. Please consult this link for more information. But make sure your visa does not expire when you are in Romania.
V. Do I need a visa?
The holders of Schengen visas with two or multiple entries, national visas or residence permits issued by Schengen Member States.
Attention! The number of entries as well as the right of stay established as per the Schengen visas must not have been exhausted. The right of stay on the territory of Romania shall not exceed the right of stay granted as per the visas/residence permits issued by the Schengen Member States.
Your residence permit is not a Schengen visa. However, as stated in Timatic, the database used by airlines:
Visa required, except for passengers with a residence permit issued by Bulgaria, Croatia, Cyprus or a Schengen Member State
So no, you do not need a visa for Romania, just present your passport and residence permit