I've essentially spent today having a meltdown. I'm doing the best I can to be "normal", but I feel like everything in my life is just pushing me over the edge. I work two jobs because I couldn't get a full time job when I was unemployed and desperately needed money. I took a part time office admin job, but the pay just didn't cut it, after about two and a half months i applied to a second job. During the interview process I told them that I had the other job so my schedule was limited. They seemed fine with that and I accepted the job. I was told I had to coordinate my schedule with the other gal of my same job title, who has been there longer than me. At first, she said that she wanted me to work Sunday Tuesday Friday. Which was fine, it worked for me. I told that schedule to my boss and my first job and she made it work, and set the schedule for the month. Then the girl said that she wanted it to be Sunday Monday, Friday, I presented these changes to my boss and she treated me like I just asked the most outrageous thing in the world. But she made it work, and changed the monthly schedule, barely making it work. Then this girl texts me today and says she wants it to be Thursday Friday Saturday so she can babysit her bf's little sister every week. I can't work at all Thursday, and can only do a half day Saturday. On top of that i'm not going to ask my other boss to rearrange the entire office's schedule AGAIN just because this girl can't make up her mind. So I put my foot down and said we agreed to the previous schedule and that was what worked for me. She starts treating me like I'm this giant burden who is being uncooperative and unfair. At this point I'm just wanting to quit the second job, but 1) I need the money 2) I'd feel bad because they put me through a 6 week training program for the job that I know cost the store money and if I just took the program and quit I'd feel like an asshole 3) I went to high school with the girl and we have mutual friends so if I up and quit and leave the store high and dry I feel like she'll tell everyone horrible things about me. Not like I have any friends to worry about anyway but that's another story 4) I have a really bad tendency to start jobs because I need money, get fed up, and quit, it makes it look really bad to employers because it looks like I can't stick out a job. But maybe i can't. I just don't know what to do. I feel like I finally do something right, find work, and now life is shoving it in my face and making it as difficult as possible. I feel like everyone at both my jobs are mad at me for not being flexible enough. I don't know what to do. It makes me want to do something drastic so that I can be stuck in the hospital or at the very least get a doctor to put me on leave. And i feel like an idiot for not knowing how to properly handle this situation. Any advice?

TLDR: Working two jobs, 2nd job keeps trying to change my schedule suddenly which is making my 1st boss mad, and 2nd job gets mad if I can't do it. Want to just quit but scared of consequences of quitting. Need advice.