Calorie deficit but no change

I hate posting on reddit but im really confused and feel like i have no other choice. Male, 73kg, 170cm, fairly big(just saying in the case that it matters). I've trying to lose fat and shred down for a hot minute and decided to TRY to do an aggressive cut and because of that i recently made my routine for cardio this: 3hours walking and 40 min running at a moderate speed mostly every day. I did that for around 2 weeks and im thinking to switch running for sparring or hitting the training bag since i enjoy it way more and my knees would be thankful. To be frank i dont track my calories but im sure im not eating anything crazy to make the cardio i do uneffective. My average day of eating is no breakfast, some meat and carbs(often potatoes but it can change) and eggs for lunch. After that i eat some fruit(generally an apple, a banana or watermelon) and for dinner kinda the same as lunch. Now since im not changing i've definetly been doing something wrong but i just dont know what it could be. Maybe what i eat has many more calories than i expected, or my body adapted to these activities and doesnt burn as much calories anymore, like i dont know im just confused and hope for some help. Like my plan is to burn as much calories as possible trough cardio to not stunt my growth since im still growing but i also want to make this quick and eating less is inevitable for fast results(also the less time i do it for the lesser are the chances i stunt my growth)Im not sure about my maintanence since people say calculators are inaccurate(in the case its needed it should be around 2500). So do you know if an aggressive cut is possible trough doing mostly cardio? And if it is do you have tips?

(also i dont want to sound like an asshole but if you want to comment about how i dont need to lose weight since im still developing etc just dont bother commentng please)