My mum says that I am not allowed to be tired after coming back from the gym other wise she'll cut my membership

I am in my mid teens and i frequently go to the gym . I came back home after a push day and I was quite tired so I laid down on the sofa . The next morning my mum started interrogating me about why I was tired (probably thinks I am lifting too much) . After that she started shouting at me threatening to cut my membership if I ever came back from the gym again tired , and banned be from going to the gym 2 days in a row . This makes no sense whatsoever because how am I supposed to do excercise without become tired???!?!!?? For reference , the most weight I lifted yesterday was 40kg on the bench for reps to near failure not total failure and that was only for 3 sets , everything else was less weight or body weight . I can't explain this shit to my mum so what the hell am I supposed to do? My life is mostly boring and gym is the highlight of the day , without it I feel like I do nothing .