My daughter has ADD/ADHD how do I help her?

So my oldest is a 4 year old girl and she’s a wonderful child, but I’m pretty confident that she either has ADD or ADHD. I had ADD as a kid and her father has ADHD. I was on prescription adderall for 10 years until I graduated. It did help, but around late middle school I learned how to control/harness it when need be, medication or not. It kept me underweight to where I needed protein shakes to stay healthy. My daughter’s father still struggles to this day at 32. She is a lot like me, although I feel like she is following the same path he did. She is a well behaved child, extremely bright and emotionally intelligent. There are days when she even tells me “mommy, I’ve been good and listened all day, but I can’t be good anymore”. Almost like she’s tired from trying so hard to reign herself in. I’ve seen a similar post where a mom asked for advice with her little one struggling with adhd and someone advised microdosing with caffeine to help calm them. I know it may sound backwards, but it makes sense to me because it aided me here and there. P.S. chocolate will not work for us, it only gets her riled up so much she acts out. I am at a loss with how to help her. I’m considering trying this method with her because adderall kept me pretty underweight most of my life and she is alreadly pretty thin by nature (not that I’m thinking about medication at her age). Does anybody else have experience with this method? Or helpful advice to help her calm down and not act out? I’m understanding since I went down a similar road, but i want to help her since she is about to start school and I don’t want to see her struggle with that aspect or get in trouble when she is trying her best. Please, any advice would be nice