Parents Blame Cannabis for Panic Attack, Don't Believe Me

I have one panic attack and my parents automatically “know” it’s from smoking cannabis. It was actually a trauma response due to a unlocked SA memory but I can’t even tell them that because it’s been a decade or more. Cannabis is the one thing that has helped (with depression etc.) but to them it’s bad and I’ve explained and they know I work in the industry yet they act like I’m new to all this and that I don’t know what I’m doing. Makes no sense because they know nothing and get mad at me when I tell them it’s not the reason.