Over weight. I do to reduce my weight?

I am a 22year old female, weighing 75kgs. I'm 5foot 4inches tall. Before lockdown my weight was 55-58 kgs, but in lockdown I have put on weight immensely. I am unable to practice any proper diet and don't even eat large quantities of food, still I'm gaining so much weight. I have joined job recently and because of time constraints I'm unable to exercise. How do I cope with this situation? I don't feel myself anymore. I'm feeling helpless in this situation. What can I do to reduce my weight? Please suggest some good practices to reduce weight. Details of my usual diet: Morning: breakfast at 10:30-11:00 am Lunch: at 2:30pm Dinner: at 10:00pm My working hours are from 8am to 7pm as I'm a newbie, I had to stay few extra hours to cope with my understanding of the job. Please help me in regards with my diet and exercise. It would be appreciable if you come up with good ideas to manage my diet in this hectic schedule. Please please give me good suggestions.