Ah, culture shock and clash, but in reverse this time (well from my perspective anyways). Have you tried talking to your roommate and explaining your situation, perspectives, and feelings? What you read as one thing may be understood by her as another. For example, what you viewed as "a good chance for them to have private time," they perceived as you being lost due to unfamiliarity with life in America; both of these are exceptionally reasonable given the different contexts. Bottling up those different readings, or misreadings, will only adversely color your interpretation of other things. Ultimately, the best way to adapt to living in the US with Americans is to not worry so much. The misunderstandings, miscommunication, and misinterpretations are expected. Many people, not just Americans, will overlook many social or cultural blunders if you demonstrate humbleness and a willingness learn from your mistakes.
-Shi Wei (美國華裔/越裔)
PS: 你也不用有這麼嚴格的態度。 大部分的留學生都碰到這種的文化差別的問題。 只要你放鬆,什麼都慢慢地懂。 加油!