How do I manage my huge student loan debt?

You are at 120K and just starting grad school? I would guess that you are looking at about another 50K per year for the next five years.?. So you are looking at about 350K when you get done. So if your average interest rate is 6% and you are being given 20yrs to pay your debt your payment is going to be about $2,310 per month. Another thing that you need to consider is that most jobs that are very high salaried have a few years internship. (Lets say 3 years) So you are looking at not making the "BIG BUCKS" for at least 8 years(if you look at the hours that you will have to put in as an inter and the amount you will be paid I would guess that you could do better working in a call center. You may work 80 hour weeks and make 55K per year = $13.22 per hour). By that time you need to understand that your loan totals could be close to 500K(at 6% add $1,458 per month in interest to the 350K). You have a 95% chance that you will end up making about $100,000 per year or less. You will have to live very lean for a short while To answer your question I would say this: live like a student until you can pay off your student loans. What I mean by living like a student is 1.rent the smallest place that you can fit into. 2. Buy a used car take care of it and drive it until it dies. 4.Buy only necessary clothing and see if you can find them second hand. ETC..... Mind you I am talking about trying to live on 15K to 20K per year (depending on where you live) when you are making $80,000 to $100,000 per year. Right now make sure that you are not trying to look like what you are going to be. Live where you are at. You are a student don't try to drive a BMW. Live as thread bare as you can. Don't live cheap(cheap is expensive because you will constantly be replacing) but live on as little as you can. As far as hating where you are I cannot answer that for you. It may take switching schools

I'd suggest you get out of your PhD program and find a job who'll pay for your further education. Also, this job should pay for your 120K loan debt, possibly consolidate the loan by going to different banks or with the company you already have the loan with. Wish you the best though! Good luck.