How do I deal with a passive aggressive workplace situation?

Recently I got a new part time job through a friend. At the workplace, this friend is the person in charge of management and is close to the boss personally. We've had a few disagreements over how some things are to be done at the workplace and on the first encounter, I chose to take what she toldme, consider it and try improve myself and the way I worked. However on the second occasion I took it more personally and got angry, especially when she told me how she hadn't reported a mistake I made to the boss. It felt like I was being blackmailed. She also constantly talks about how I should behave the way she wants me to as she was the one who landed me the job, how she would never do anything that would lead to anything detrimental happening to the establishment and about how stubborn I was and how I don't listen to her. She also keeps bringing up past mistakes I had made during my training period as to reinforce now troublesome I was. Also how everything I do only reflects me and that she had nothing to worry about as her position within the establishment was guaranteed as a result of her closeness with the boss. I feel there are veiled threats in the way she speaks to me and that its very passive aggressive.
I have spoken with the boss when she asked me about it and she advised to keep working well the way she (the director) asked of me and if anything comes up, to talk to her about it. The second occasion we had a confrontation I was so distraught I immediately called the boss and spoke to her, also mentioning to her about the mistake that my friend hadn't mentioned to her about. I told her it was my fault and wouldn't happen again, just so I didn't have to face feeling like I was being blackmailed by my friend. The boss told me that I am working well and to not worry about such things but to keep up my work. I felt better after speaking to her at length as I realized I need not have reacted or taken things that personally.The next day was my day off and I found that a meeting had been held to discuss matters and establish a routine and strict roster at the workplace. This resulted in the next day she (friend) yelled at me following and said "I now know that one of my friend's is a tattle tale" as the boss had brought up the matter of the mistake I made that my friend had allegedly not reported in the spirit of friendship. I was disturbed by this. On thinking things through, I feel that I was influenced by the things my friend had said and I am in this position as a result of reacting to what she said. My boss has not contacted me personally to bring up any of these alleged issues. Everything I hear about the decisions the boss has made is through my friend but I am very distrustful of her as I feel the way she delivers the information to me is different (i.e: more aggressive and confronting) from the way the director would actually have imparted her decision.
How should I proceed and what should I do to improve both my mentality and workplace situation?
Asked May 13, 2016

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