I think the most important thing is to trust the process. Yes, you have to give some things up. You also get to put lovely food in its place. If you do it and follow the rules, then it works. If you don't, it won't.
Believe me, I had tried ever diet going. I knew the calories and fat grams of everything. I kept getting fatter. Starting bootcamp last May was last chance saloon for me. I decided I had only one rule - to follow the bloody rules. No exceptions, no tweaking, no arguing that I had any special reason for aberrations. I said I would do it to the letter for the 10 weeks of bootcamp (which included a big wedding anniversary and a two week holiday). If I didn't lose 7lbs in those 10 weeks, then I would stop it, never diet again and try to find peace with my weight. 7lbs sounds modest, but it was more than I'd ever achieved before. In fact I lost 21 lbs in those 10 weeks - so a bit like old Forrest Gump, I just kept on doing it. And a year on, I'm 70lbs lighter. My GERD has gone. My IBS is improved by about 80%. I feel 20 years younger. I sleep well. I run (no one more surprised than me by THAT!).