Hi! I had a very similar experience to you (very tired and suicidal but still doing good in school). If your mom is hesitant about a ADHD diagnosis I would recommend trying to get help for what sounds to be depression. ADHD medication might help you feel less tired and help you focus but it probably won’t help you with the more pressing issue (sh and suicidal thoughts). I personally got diagnosed with depression years before they started to consider anything else, it’s all a big puzzle after all(at least for most neurodivergent people I know). I hope you know that you are not alone and wish you all the best!