Hi there. Unfortunately, there's no simple answer to your question - or at least not a single one that everyone will agree with. If you're new to nutrition, its easy to get lost in the details, counting calories, protein, fats, carbs, etc.
About the best, most GENERAL rule to follow is to keep your diet as natural as possible, choose leaner meats like chicken or turkey, and stay away from the obvious downfalls like sweet breads, candy, ice cream, etc.
If you're having trouble with cravings, I would suggest giving yourself 2 days without any grain products or sweets. Instead, fill up with fruits & veggies. It will be a rough couple of days, but it will get easier.
There are lots of people on here, willing to share support and advice with you. Just reach out.
If you can spend years beating yourself up mentally and remain standing, you can HANDLE a few muscle cramps and cravings. A little pain has NOTHING on feeling insecure. Remember that next time you wanna quit. You can do this!