Advice on Weight loss needed!

HI there i am a 20f and I weigh about 145lbs. I'm 5'4 and until college I was always around 115lbs. I suddenly gained like 20lbs and it's been a year now and I haven't been able to shed it off and i keep going up. I have a hard time staying consistent. I'll do agressive keto for a week and then see a few pounds go down and then i get off track. It's mid feb when I am posting this but I am going to florida for spring break in exactly one month and a few days. I really want to lose around 25lbs in total but for this trip I know that is unrealistic. i want to be able to be down atleast 12lbs and look good. I need advice because I don't know what to workout in the gym in order to look slimmer and just how to stay consistent. I truly don't care if any of the methods are safe or not I just really need to lose this weight. Thank you and please let me know!