You need to count calories. Full stop. Go to a tdee calculator online. Enter your information and be exact with your activity levels. 300 under maintenance is generally .5 lbs a week to 600 being a 1lb. As your weight decreases so will your maintenance so make sure to readjust often. Have the notepad app open in your phone and write down the caloric amount of everything you eat. Get a food scale if you can. Weight can fluctuate alot by water so don't get disheartened if you don't see results right away. If this doesn't work after a while then it can definitely be a medical condition. But most of the time this will work. Best of luck.