First off, I'm not an expert, so take this with a grain of salt. However, I can pass on what I've learned from my dietitian. If you can book a visit with a good dietitian, that would be super helpful. They can figure out an exact number for your deficit and give you meal plans to ensure you're getting the right proportion of protein/carbs/fats. It's a lot easier than trying to figure those things out on your own.
I would not go any lower than a 500 calorie deficit. That would give you about 1-2 pounds of weight loss per week. It may not get you to your goal by June, but it's a manageable and healthy amount. Losing too much weight at a time can cause health issues.
Staying hydrated, getting plenty of sleep, and managing your stress will make your weight loss journey (and life in general) more enjoyable. Eating healthy foods and getting moderate exercise will also help you feel better and give you energy!