Calories, and exercise and ... balance?

- Once upon a time in high school I was 6"4' and 185 lbs, a thin bean pole of a man.
- I got up to 275 lbs thanks to university cafeteria food... crap will take years off your life.
- Worked all the way down to 215 lbs...

- Made a mistake and got into an unhealthy stressful relationship, and economy was tanking at the time.
- bam back to 280 lbs over a couple years...

- Ditched the fail relationship, work has been improving, and I am tons, tons, tons happier.
- In about the past half year have lost about 30+ lbs.
- Now spring is here and I find myself walking 5 - 7 miles per day.
- My work is sedentary, and so my 1300 - 1500 cal diet seemed fine.

- But with new exercise I am burning half those calories, yet I don't feel like I can really consume that much more without feeling stuffed.

Am i going to be hurting myself if I continue this, or ??? How do you MAKE yourself eat more without a lot of empty calories from junk food.