By the way, living with a roommate is a good idea regardless, as a first year teacher - spread and share the bills. Your electric bill is nearly the same for 1 or 2 people - most of it comes from heating/cooling and cooking/clothes dryer. Water bills are higher, but not substantially so, most are tiered for levels of consumption. Cooking for two is not twice as expensive as cooking for one, either.
Here are some ways to stretch your budget:
Never eat fast food if you can help it. It costs more than making the same thing at home. You can make a dozen tacos for the cost of two value meals at Taco Bell - and you've got lunch for the rest of the week. Beans, rice, and dry pasta are your friends. Learn to cook!
Spend more money on clothes for the things that matter. Buy pants at Wal-Mart/Target/your discount location of choice. You WILL GO through pants at a rate of 2-3 pairs a year - torn on your keys, ripped up on a drum, oil stains, etc. Don't buy pants that cost more than about $30 a pair. If you want to have some nice clothes for yourself, do not wear them to work frequently. You can also do with nice dress shirts and tops if you want, but pants need to be the cheapo ones.
Never buy things that aren't on sale. Coupons are your friend.
You don't need home internet AND internet through your phone AND cable. Any decent TV worth watching is available on streaming for $5-15 a month, as opposed to a $50-75-200 cable/satellite bill. If you pay the extra $5 a month, you can use your cell phone as your wifi at home too.
If you drink, stop drinking outside your house. Buy at a store and bring it home. A glass of beer at a restaurant/bar is $5 to $7. Mixed drinks can be up to $12. A six pack of that same beer is $8 at home.
If you do, stop smoking. You're throwing away $50 a month even if you only smoke a pack and a half a week.
Go to the doctor every six months. Go to the dentist every six months. It costs less for preventive visits (and they're in fact reimbursed or free on most insurance plans) than it does to let something go until it's serious.
Never lease a car unless you're sure you want to pay for it forever. You'll never own the thing, and you'll start over on payments in 3-4-5 years. Buying new is rarely cost effective - you will pay more than twice the worth of the car over the time of your note. Pay in cash if you can, but don't be afraid to set a car payment. Do the math yourself. If they say $400 a month times 48 months, with $5000 down, are you getting a $24,000 car?