So I need some advice/reassurance ;

Here's the story..

Monday I started a new job, basically staring at the computer & talking on the phone for 8Hours. Well, I get really bad migraines, I do wear glasses all day. I haven't learned any information at all. I can't focus on the computer. I honestly don't know how to work the system what so ever, even after being shown for 16Hours (2Days of work) my headaches are so bad I come home crying every night. I think the best option for me is to just quit & try to pursue treatments for my headaches. Tonight (Tuesday) was much worse than Monday. Am I wrong for wanting to quit after 2Days?