Work .... This is a long one, sorry

I have a boss who truly does not like me. Everyday I go to work and and I try my best in my head I think I am doing a good job, but my supervisor seems to be always putting me down and like picking on me. Yesterday she called me in her office 5 mins before I was to leave and and blamed me for something that was so outrageous it was like she pulled this accusation out of thin air. Then she hit me with my job performance basically sucks and I have animosity towards her and others if you knew my personality you would know that is crazy talk. I feel like I have to walk on eggshells around her. I can't quit cause I am the only one working full time but I feel lost. I came home one day 3 weeks ago after her screaming at me for giving her a call that the person specifically asked for her but it was to do with someone else and she screamed at me. She is Portuguese so am I too, but not full blooded like her and everyone else. I am the only one who does not speak it and when we are all together they all speak Portuguese knowing I don't. She had a summer party at her house last year and invited everyone in my department, some from another department, but not me. When someone asked if I was going I just acted like a knew nothing about it and I felt like I got a pity invite after someone said something to her. I came home and cried as soon as I got in the car and my 4 yr old was there and now he always asks, "Is your boss still mean to you mommy?" I know I have to find another job, but there are none out there and I feel lost. I am just so upset to think I am doing a good job and then find out I am actually doing a bad job. I am a people person and work as a secretary at a very busy orthopedic office. I get complements from all the patients all the time how friendly and nice and all the doctors like me that's why I just don't get it. Any advice?