I have adhd and I have the exact same problems, honestly you should let your teacher know, but if you don't just do things like taking breaks instead of studying for long periods of time and stuff. I can't really help you because I take a prescribed medicine that helps me focus and melatonin to help me get to sleep (because of my adhd). I started taking my meds and melatonin since 5th grade, and I was diagnosed as having adhd literally since I was born, your mother is being a bad parent to put it plainly and you need to make her listen to you or tell another adult and get them talking to her because if she's not meeting your basic needs as someone with adhd (if you have it) that's neglect. hope you feel better soon.
I would suggest to try to drink water, stay hydrated, and maybe do a bit of a workout in the morning. Netherless, try to sit down and have a talk with your mom again. Explain thoroughly your troubles and dont give up!
recently ive been concerned about having adhd, ive shown symptoms my whole life but my mother refuses to get me diagnosed because “im just being a teenager”. ive been struggling with motivation and my grades have been bad too because i feel like i literally CANT do my schoolwork, its been exhausting these past few weeks and i always feel tired. any advice on how to gain more energy and focus more?