I can understand your concern. Considering your age of 23 years, an organic illness is very unlikely. Memory problems in your age group is mostly a presentation of anxiety problem. It is usually secondary to In-attentiveness or difficultly in concentration which is a core symptoms of anxiety problem.
Next Steps
I would suggest you to consult with a psychiatrist. With suitable therapy and if required medications it can be completely cured.
Health Tips
Don't worry. It is not a memory problem But anxiety issue that apoears likely here. Anxiety disorders are one of the commonest problems seen.