Quitting job due to declining mental health-need insight

Hi everyone, I am having a bit of a dilemma and need some insight. To start off, I have an incredibly strong work ethic. I have consistently had at least one job since I was 16 and I am now 25. I worked full time while also attending college full time. So this is not a post whining about being tired, it’s actually kind of the opposite. I realize I am somewhat of a workaholic. I currently work 4 jobs (3 that I love and use my degree for that allow me to pay the bills) and one that subsidizes the rest of my income and allows me to be comfortable. I hit anywhere between 50-65 hours a week. Over the past month or two I have noticed and felt my mental health declining drastically. At first, I thought it was somewhat hormonal or related to a current romantic relationship that didn’t turn out as I hoped. However, I’m starting to realize it’s because I am stretched THIN. I basically have no free time as I currently work 7 days a week, usually from about 10 am-9pm with small 1 or 2 hour breaks thrown in. I currently live with my brother and my niece (I act as a babysitter when he needs it and pay $200 a month for “rent”, so my living expenses are pretty low and easily manageable with my 3 other sources of income). My dilemma is this: I am not in a good place right now emotionally or mentally. I do enjoy working, but I also realize that this schedule is starting to take a major toll on me. HOWEVER, I am hoping to move out of my brother’s house and into my own apartment by this coming summer. The income I would make between my 3 other jobs if I were to quit my 4th would still allow me to save quite a bit each month and probably achieve that goal, but not as easily as if I kept the 4th I am currently working. I just don’t know what to do. Moving out is very important to me, but I haven’t been in this low and dark of a spot in some time. Any insight or advice?