Congrats on the Diet and Loss Jsaad, losing weight isnt hard to do, its the motivation to lose the weight every day and fighting temptation that is hard.
When I went into college I was at my playing weight of 205 and 6% body fat and in great physical shape. By the time I had left college I had grown to a very sexy 250 pounds and probably 20+% body fat. It wasnt a cute site. I started to eat right and workout often. I went from 250 to a very slim and lean 185 in a little over a year. I have since put weight back on and I am now back to 202 and about 10% body fat. I am 6'3" and now 31.
Lastly about diet sodas. Very bad for you. The human brain uses glucose(sugar) as its energy and when the body is lacking sugar it exhausts the body and creates sugar cravings. Okay so when you eat a naturally occurring sugar, fruit, the glucose is fed into the sugar reflex in your brain and processes that sugar into energy and also tells your body that you dont need to crave because you have fed a need the body has wanted. Now if you use any of these, Nutra-sweet, Splenda, Equal, or anything with Sucralose, Aspartame, Saccarin or any of the like what it does is sends a signal to the brain telling it that it has received its sugar fix, but after it has been processed the brain realizes that it has not received any sugar at all and thus goes into cravings because you promised it energy by eating a sugar like substance but really just tricked it. So the brain will do what it takes to get energy and will make you crave food to help feed it a sugar to regulate its glucose levels and satisfy its energy fix. I hope this helps in a layman terms.