do i have ADHD?

i’m 14 years old. i have severe problems with concentration and fidgeting and being restless especially in a place (such as school) where i have to sit still and concentrate. i also have problems remembering things very often. like i have a reallllly bad memory. my memory has always been a bit off but not as much now however i have been through a few traumas that i think triggered this. throughout the day i get very happy, hyper dizzy and reckless and then i go back to being sad and tired and my mood goes up and down like this numerous times in a day. i also have alot of fits of anger and sadness ( i don’t know if this is anything to do with it ) and a short temper. what do u guys think? and what should i do?