I need help. Eating right and exercising but no results...?

Hi everyone I'm having a huge problem. I'm a male weighing in at 280 lbs. I started a diet and exercise regimen a month ago working out ~45 minutes everyday and eating about 1800 - 2000 calories per day. Everytime I have done this is the past I have lost lots of weight I lost about 100 lbs 2 year back by doing this but sadly put it all back on. This has been a difficult struggle for me and today I weight 280lbs like I did last month... I've talked to dietitians and nutritionists as well as trainers and followed everything. Ive made myself crazy listening to everyone and this is my last hope. I'm a 23 year old male and am fairly active... Please help.