I just started my 2-yr postdoc, but things have gone sour really fast. So, I really need some career advice as to what to do.
Over several months, I did the interviews with the supervisor and the lab and things seems to be really great (although I got a strange feeling that the lab members were trying to deter me from joining, see below).

I joined the lab last week, and the condition of the lab and the equipment was really poor (but the supervisor said it was great...), but I got along with the supervisor and the lab great. However, this week took a turn for the worse. My supervisor has been vicious with me for several days and we have had a major conflict almost everyday this week, which I believe is a bad sign when something like this happens when starting a position. The other members of the lab said that the supervisor is normally abusive and they are not on great terms with her either. As I said, I met with these lab members via Skype over the summer and I felt that there were trying to warn me not to join the lab, and today they confessed that this was true. I heard several stories about the supervisor being vicious with them over small things (i.e. asking for vacation) after telling them about my fights with the boss. One of the lab members did file a formal complaint against the supervisor at one point.

I am concerned about the supervisor and more concerned that this is not going to help my career at all since the mentoring by this supervisor is poor quality (this is how the other lab members feel after being there for almost 2 years. They are leaving immediately after that). She has promised a good work environment, additional pay to the NIH base pay, flexible time off and great equipment, but all of this is not true. The other lab members confirmed that this happened to them too. Basically, this supervisor promises a lot of things and does not deliver.

So with all of that being said, is it wise for me to leave ASAP and look for a better opportunity OR is it best to stay put and complete the 2-year postdoc (or most of it). I don't favor leaving a job this soon and would rather give things a chance, but this place has been extremely BAD. Furthermore, the lab members feel that this is not a good workplace and confirm that the behavior of the supervisor will continue (they have their reasons for staying, but really regret joining). For these reasons, I don't feel staying is beneficial to be perfectly honest. 

I would rather not have to ask for advice about this, but I am in an uncomfortable situation and any advice is extremely appreciated. Hopefully I expressed this clearly... I'm kind of a mess right now.