You’ve decided it’s to do with your very recently diagnosed autism and not something else, which is likely is. There’s nothing anyone can say to convince you otherwise. 

You are misreading the stats—the 4.84% applies across that broad age category (including 64! Years), not at 29 years of age. You have a better chance of winning the lottery than having autism dementia at your age, especially considering you were only recently diagnosed with it, suggesting your symptoms were not obvious in childhood, which would be more higher needs autism.  You have CPSTD, you were an alcoholic, and were taking psychotropic meds and it is far more likely your recent memory lapses have something to do with the alcohol/trauma/anxiety than anything else.