All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If you are in a dire necessity for doing this job, then you are not sinful, Allaah willing; the extent of necessity that permits committing what is forbidden, is when one is sure to die or face a hardship which is difficult to bear if one does not commit this prohibition.
You should look for work elsewhere and when you do find another job, you are obliged to leave this forbidden job.
You should avoid mixing as much as possible and not stay at this mixed environment except according to the necessity, in a way that after work, you should go home.
For more benefit, please refer to Fataawa 82399, 82617 and 88465.