How do I quit my tutoring job?
After speaking to some peers, I've realized I've been naive. I accepted and have been working at a company that, I suspect, isn't doing payroll deduction. A lawyer friend told me that this is likely the case because they don't provide paystubs, only e-transfers. Doing the math myself, after tax deductions, I'm paid around $13/h. (Don't quote me on this though; I need to check with them. If I'm wrong, then I'm making minimum wage).
It gets worse. I accepted a student outside of my qualifications. This was a foolish move, but I did it because I thought we would be provided with prep material (all other students I've had have come with sheets that I prep for in advance). I don't know where the miscommunication happened, but I think I would've been able to handle things with sheets. As it stands, I'm having to prepare all materials independently (including a study plan and progress reports), and study a wide range of materials before our sessions (it's hard when I don't know what I need to cover exactly). For 1 paid hour, I need at least 8 hours of prep time.
If I add gas prices and prep time to my rate, I'm actually earning about 30 cents an hour.
This June, I have another gig coming up that is way more important and relevant to my longterm teaching career (it's an actual teaching position). If I stay in this job, there will be a month-long overlap, and the student is likely to book more hours with me during exam time. It will be very bad if I end up with 5 hours of tutoring (and therefore 40 hours of prep time).
I morally feel really bad because I misjudged my abilities, and therefore have put myself in a situation where I've overpromised and underdelivered, but at the same time, they did have access to my educational history and should have had an idea that I wouldn't be good enough for this role (I do have some experience in the subject, but it's limited).
Basically, quitting is the best option. Everyone I've spoken to has told me it's not worth it to stay, but I can't get over the fact that I'll be letting down my admin and the student I'm responsible for (I'm the only person in the facility who can "teach" this subject).
How can I quit amicably?
Edit: I'm a recent grad.