Thinking about leaving a master's program I'm at the end of my first year in a food science master's program, with full funding at a good university and I'm seriously considering dropping out. 

I completed my undergrad in biochemistry and my research project is more focused in yet another field, which I have no experience in. When I applied for grad school, I wasn't exactly sure what I wanted to do within the field, but figured I could build interests along the way. I only received the one offer from a new professor that would be starting at the same time as me. I didn't want to let the opportunity slip by and I genuinely thought the project was something I could get interested in. So I packed up my life and left behind most of my support group. This was extremely difficult, as I have a very close relationship with my family and my mother has recently been very ill. Not long after beginning school, I began seeing a therapist as my anxiety (which has always been manageable) started worsening. The majority of my coursework has been undergraduate classes that I find completely uninteresting. We are only required to take 4 graduate credits and I wasn't thrilled with my choices (there are only 2 classes available). The department itself is small, obviously favors the undergraduate population, is extremely unorganized, and most of the lab groups are cliquish (seem nice enough, but not entirely welcoming). Since my lab is new, I'm the only student and the only other researcher is a recent PhD graduate from another lab. I was unable to start much work on my project the first semester because I didn't have what I needed. Now, I've experienced numerous setbacks with contamination and other problems. Not to mention, since the beginning of the new semester, my anxiety has become borderline debilitating and accompanied by moderate depression. In a recent conversation, my advisor expressed concern about my lack of work (which I take to mean, lack of results, because it's not like I've been lazy and unproductive), even though he is aware of the problems I've faced. As far as advisors go, he is just out of his post-doc and is relatively nice, but is extremely forgetful (never remember anything he tells me/I tell him), unfamiliar with the program requirements even after a year in (meaning, I have to get help from anyone but him when it comes to courses), and occasionally makes backhanded comments to me that I find insulting. Overall, I just find myself extremely unhappy. And the prospect of moving on and getting a job just seems freeing to me. 

However, I'm not sure how I would go about doing this. There is no formal policy on a leave of absence, so if I wanted to make the leave less permanent in case I change my mind, I don't know how this would work. I'm also not sure when would be the best time to drop out. Regarding withdrawals, the grad school website says that any students receiving tuition remission (which I do) are "responsible for their entire tuition assessment." I'm not sure who, if anyone, I can talk to in the department. I have yet to begin my thesis, 2 courses left to take, and likely have 2 years left because of setbacks. Does anyone who has left grad school or considered doing so have any advice?
You don't find the field you're in all that interesting. That may be because it's not the right field for you. However, depression can make everything seem uninteresting, even activities you used to love. Maybe you just need a break. Your therapist is probably the person to help you figure out what's best for you at this time.

If you decide to take a break, I'm sure your university has some sort of student ombudsman or student services office that can guide you through the process of getting a leave of absence. Look on your university's website, or ask the registrar's office, student health, or the student union.

The setbacks you've experienced in your research don't sound that bad. A few false starts in research are quite normal. One year into my own master's, nothing was working and I was sure I wouldn't have any useful results. My advisor helped to calm me down, and all turned out well. It sounds like you and your advisor just don't "gel".