Please help me I'm having a mental breakdown!:(

Hello pals!
I'm a 17 year old and I'm 5'5" and my weight is 145 pounds currently. I was able to lose 10 pounds in 2 months with diet and harf workouts and I felt so great about myself. It's been close to 3 weeks that I haven't been sticking to my diet and lately I have been eatinh awful I eat healthy for the start of the day and then I just start getting crazy and eat like 6 oreos and so much other junk! I have also been going to the gym less I have promised myself to start a one month low carb diet to get back on track and to go to the gym 5 times a week(I love the gym tbh). However I have been reaalllly struggling lately because I'm down to my last 10-15 pounds so it is really hard to lose these last pounds! I wanna lose 10-15 pounds by the end of June of 2017. I loveeee sugar and it is killing me ugh I'm going crazy tbh I feal guilty and horrible 95% of the time. What should I do? Should I get an appointment with a nutritionist? should I get a gym trainer? should I get an online weight loss membership? Plz give me some tips I'm honestly so disappointed and exhausted and sorry for my horrible typing.