ADHD WITHOUT HYPERACTIVITY ALSO KNOW AS ADD INATTENTIVE?

if anyone has a story about how they found out they had it or symptoms they have because of it please respond back if you have time. I and everyone else has been reading up on it and theyre getting me to see a psychologist because theyre pretty sure i have it. I also heard its hereditary and my brother actually has adhd. Also ive been diagnosed wit post traumatic stress disorder and someone said that this may make me seem like i have adhd without hyperactivity but i think he was wrong because alot off the add symptoms im experiencing arent caused by PTSD at all.