Manager Problems

I am currently having problems with a manager at my job, who seems to target me and only me. Out of the other employees who work my shift, I am the only one who is required to bring in a doctors excuse if I call in sick(where the other employees do not require one, or the manager in question only inquires by phone if they are 'better") and calling 'out' of work other than being sick, the manager will take whatever excuse is given. However whenever I have had to call out or even be later than usual due to either a flat tire, family emergency, etc. she has written me up and suspended me. Even while I was pregnant and had a false contractions occur on my On Call night, I was written up because I was called into work but was IN THE HOSPITAL BED and could not come!

Tonight for example, is my on call night, and one of her 'favorites' called out sick 12 minutes after getting to work due to 'might have food poisoning' though he had NOT been in the building for TWELVE MINUTES AND NEVER LEFT THE OFFICE. She accepted the excuse, did not ask for a doctors note, and called me in tonight...and also threatened to write me up because, this morning at 8:30 AM, I HAD to be at the office to sign paper work for my yearly office wide renewal of health benefits, and after that had to go get my medicine from the pharmacy. Then I had to get my oldest son from school because he was sick, so I did not sleep until 12:00 in the afternoon like I usually do on my on call days. So when I told her I can come in at 12:00 AM tonight instead of 7:30, she threatened to write me up!

This manager actually was released from the company due to medical reasons(ulcers due to heavy drinking and stress...) and re-hired this week. She threatened my job from stated earlier AND from when I left work one evening after throwing up in the trash can IN the office, of which I had to go to the doctor to get a note to VALIDFY my sickness. SHE WAS NOT THE MANAGER AT THE TIME, NOR WAS IT AN UNEXCUSED OR PUNISHABLE ABSCENCE.

What do I do? Is this just a "suck it up and deal" or "find another job lol complainer" type of situation?

I cannot go to any other manager because they will only tell me "I am not the manager, talk to her."