I Am Tired Of Misdirected Bull Crap Hitting Me

I think I have ADHD I had a opportunity at getting a job today and I screwed it up due to forgetting instructions and not being able to focus I messed everything up . I feel so dumb and useless right now plus I've been stressed lately this really sucks for me . It's like I am delayed mentally everyone was advancing except me I was behind . I did everything wrong and messed up ugh I hate my life . Idk what's wrong with me but I failed the job opportunity I could of had in the future this really sucks .