what am i doing wrong why am i not loosing weight

i did a diet last year and i lost 12 kg  but i still nedded 10 kg to get to my perfect weight,im 1m72 cm and now 73 kgs i would do about 45 min of treadmill 4 or 5 times per week, but this summer i decided i want to get to my perfect weight so i did everyday 4 hours of work out witch includes classes of cardio and 40 min treadmill and 40 min eleptycal and muscles training but i did not lose any weight some people told me its because im gaining muscles but i feel very disapointed that i worked SO hard i would even do abs and dumbles exercices but all for nothing so when i see my weight still the same i would leave my healthy diet and eat whatever i want for a day or 2 but then realize i dont want to get to the fat person i was so id get back to the diet but then i back to eating bad food,u can see my eating behaviors arent stable.Yesterday i had alot of cake so i decided today ill start healthy but i had to have some of that cake so i ate a big big slice of it but spit it right away and i tried not to swallow any salivia but i feel the sugary taste in my mouth so i feel like i did eat the cake and i did gain calories.Anw would someone just tell me what im doing wrong in my exercicing and in my eating behavior( the eating and spitting i do it very very rarelly)