how can i eat a maintenance diet without gaining weight if 1000 calories a day is maintaining my weight?! i dont want to be stuck on 1000 calories for the rest of my life!

It very very very simple.
Do some excercise,...,..,.,.,.,.,
If you do a lot, you can eat as much as you want

If you're not losing weight at 1000 calories a day, then one of these things is happening:
1) You're not counting your calories right
2) You are TINY
2.5) Your metabolism is crap.
If it's 1...pay more attention.
If it's 2, nothing you can do.
If it's 2.5, need to start working out and eating more. Both those things will help raise your metabolism.

Eating a low amount of calories, like 1000 is not healthy, nor will it make you lose weight in a healthy way. By eating less than 1200 calories you could be putting your body into starvation mode.
Furthermore, losing weight is about burning the calories that you put in. If you upped your food intake to 1200-1500 depending on age, weight, goal weight and time frame, you would simply have to do enough exercise to burn enough calories to lose weight.

You dont need to restrict your calories if you are eating healthy food. Exercise, eat healthy, and drink a lot of water and you will have no problem losing weight and keeping it off for good. Dont count calories, make calories count.