Im only in my 20s but have a hard time remembering things if i dont write them down. could i have a memory problem?

Attention Problem: I doubt that you have any neurological disease with these symptoms. But you very well may have an 'attention' problem this can easily be diagnosed at a psychiatrist's office with the right testing for this problem.

How R U sleeping ?: The info lists your history of adhd of which 30-50 % will have some additional issue like short term memory difficulty, learning disability, etc.One of the more common reasons for memory trouble is ineffective sleep.If you are not getting good sleep, probably 8 hours, you might improve this with better attention to this factor. Balanced nutrition and exercise also help.