FMLA Leave? Should I do it?

I‘be been working at a top 10 national public accounting firm for almost 3 years. This year I’m officially done with my exams. I’m not major in accounting so I had to take 5 summer classes during work to fulfill the credits requirement. After the classes are done I felt mentally exhausted that I couldn’t do this anymore. I was sick for a week and can’t focus on my work anymore. During the past two years I was struggling with my exams and work and never an above average performer. I felt that it was time to switch job but didn’t even have the motivation to apply for new jobs. I went to my doctor yesterday and got the paperwork for FMLA leave for 2 months, but was hesitated to turn in. The guilt of leaving my team during busy season, the thought that the managers and partners would despite me because they would think I’m faking it, that it might hurt my next career, what if I’m stressed because I’m just bad……all that thought made me scared to summit the request. I decided not to go back to this position after, and will need a couple months between jobs. A FMLA leave is a great option for me but I don’t want to hurt relationships with my team or my career. Should I go take the leave, or just quit?