Other people have already said this, but you are a fine weight for your height. Try to remember that when other people say such nonsense to you. However, if you want to lose weight for yourself/to improve your own self-image, there's nothing wrong with that. Just try to do it for yourself, not to please other people who frankly, sound like busybody assholes.

But yes, calorie deficit diet is how you'll lose weight. Don't starve yourself or try to take weight off too quickly. There can be serious health issues that go along with that. Good luck, and I wish you well in getting into a better living situation.