I have so been there. You are not alone!
We are working with a therapist to help us cope, and provide us with strategies. Our son, also 9, takes adderall. When he flies into ODD, I call it what it is: a tantrum. I tell him, you are having a tantrum. When you are ready to be respectful and calm, we can talk about what has upset you.
It didn’t start working overnight. it has been a year or more of work: praising the good behavior, ignoring the bad, one small incremental victory at a time. In the worst of it, I felt like I had no love left for my child–which just hurt so much. It really helped for me to understand (from our therapist) that his bad behavior, his tantrums, were calls for help. I had to look really hard to find things to love/praise. But that positive feedback built on itself and slowly restored the balance to more positive, fewer ODD/tantrum days.
Hang in there. One day at a time.