S.B.
Well, V.,
I'm not sure you can sue your company for not scheduling you. They haven't fired you and offered to let you have a stool, but you still had your fainting problems. My guess is that they are worried something could happen to you if you faint and fall and hurt yourself.
You say you have fainting problems at work, but do you have the same problems while attending high school?
What has your doctor said about your fainting spells? Are you eating right? Are you anemic? Are your sugar levels in check? Does he expect these spells to diminish as your pregnancy progresses? Has he talked to you about putting you on disability leave until the fainting goes away or your baby arrives?
I would talk to your doctor first.
I don't know that you can sue your employer for not scheduling you since if you faint and get hurt there, then you could sue them if you hit your head or something, It sounds like they haven't scheduled you, but they haven't terminated you either. They probably just don't know what to do. You already fainted at work and had to be taken to the ER. They are probably concerned about you and about their liability as well.
I don't think you can sue them. That's just my opinion.
Talk to your doctor. Your employer may want something in writing that says your fainting is over or you can't work until it subsides. Maybe you are just doing too much between working and school.
The main thing is to take good care of yourself.
Best wishes.