What am i doing wrong?

any other time in my life if i wanted to lose a few pounds all i had to do was cut back my eating and hit up the treadmill and i could lose 5-10lbs in one week. granted it never stayed that way because we all end up gaining it back. but anyway this time i got serious! SERIOUS serious! i started counting calories. limiting myself to 1500 or less a day. mostly i buy a lot of lean cuisines. and for dinner i eat either salmon or chicken with rice and steamed veggies. however i will admit, every now and then i'll splurge and eat a burger or have soda but i still keep counting the calories and cut back in other areas. or try to eat healthier items if i am forced to eat out. and then i make up for that burger on the treadmill. along with that i have been working out 3-4 times a week. usually for a good hour to hour and a half. combination of cardio and light weights. usually i do squats and leg lifts. then i dance with 2lb weights focusing on twisting and flexing my tummy to try and tone it. along with other leg movements. then i get on the treadmill for 30 mins and do a minimum of 300 calories and 2 miles. i do however do my workouts in the evenings as oppose to the mornings. not sure if that changes anything or not. along with all that, i take a prenatal vitamin and drink 2 tablespoons of apple cider vinegar daily. I've been doing this now for a month and a half. in the mix i even hiked Yosemite national parks half dome hike. which is 16 miles long and takes 12 hours. You would have thought i'd lose 10lbs just doing that hike. but the crazy thing is, i haven't lost any weight...i'm perplexed. i can't even lose that easy 10lbs i use too and im only 25 years old. its nuts but my morning weight is around 142-144 and once i eat and go about my day, my nightly weight is around 146-148. but its remained that way. I know what you will say, im building muscle. MAYBE but i just don't feel like im changing at all. im not even seeing it in my clothes either. my jeans are still tight as can be. I just don't know what im doing wrong. I'd like to lose 15-20lbs. maybe one day it will all just fall off, IDK...anyway any tips would be nice! thanks!!!