HELP ME LOOK GOOD FOR MY BIRTHDAY

so I really let myself go after getting into a relationship for the past 3 years and just eating very unhealthy. I’ve always been skinny but getting a desk job has made me gain weight. I feel so embarrassed to wear the dresses I used to wear and I have rolls when I sit down now. I’ve tried a lot but nothing seems to work. I currently weigh 145 lbs and used to be 115 like 4 years ago. Then it went to 125, 135 and now 145. The incremental 10 pound weight gain is bad and I don’t wanna wake up super overweight one day. I want to be my confident self again. Any meal ideas or workout plans? I have fat arms genetically so it’s really hard to get thin. I’m trying to lose 15 pounds in 2 weeks for my 21st birthday. I know it’s bad to have rapid weight loss but I’m desperate to fit into my dress :( Any advice is strongly appreciated. THANK YOU ❤️

Before at 125: