Losing weight troubles/need help!!!!!

So last year I lost Alonso 40 pounds from February to June. I looked pretty good even though I could have kept going. I am currently 5"4 and constantly fluctuate from 240-250. I want to lose 20/30 pounds by the end of April ( that's when prom is and my date is a guy I have liked forever.) I went with a backless dress that has mesh on it, and I'm kinda regretting it honestly. I have a lot of back and bell fat that I need to get rid of! Any suggestions on working out/ anything else to lose that weight? I'm gonna cut out all fatty foods and carbs. Thanks for your help guys!