Need Help Getting Back On Track

I'm eighteen years old, around 5'2", and as of today, I weigh 160 lb.
For my height, ethnicity and muscle mass, I am around twelve-fifteen pounds overweight. But because the extra fat is added only to my back and belly, this looks a lot worse.
I've been trying to work on my body (mostly through walking because I have a knee injury that prevents me from doing too much) and by January of this year I was down to 149 lb on the scale with not much to show on my body.
Then my semester exams hit and the scale started tipping in the other direction.
Part of me wants to give up, like I have every time my attempt at losing weight fails, but I think that with a bit of help, I will be able to get back on track.
How do I lose weight in a way that
-I also lose fat on my body?
-I don't have to put in a ton of extra time or money (I'm a student so both these resources are limited)
-I don't have to make any changes that are so drastic that I will give up on them after awhile (such as completely forgoing sugar or carbs)?
Any advice would be really appreciated:)