thank you for your query. first of all i would like to tell you that there is no cause for alarm at the moment. what you are describing happens to be a very common problem in individuals of your age group. It may be due to a number of causes, like an underlying depression, anxiety or adjustment disorder, which needs to be diagnosed and treated if present. also, significant life stress (particularly financial, social etc.) further compounds the problem. While in school, a person has very little responsibilities, and is mostly focused on his studies, thus giving attention and retaining study material information is easier. But coming to your age, obviously, you have a lot of other activities and engagements that needs to be taken care off, thereby, diverting your focus. However, once the underlying cause is identified, your problem can be managed more easily. A detailed history, and mental status examination is required to reach a definitive conclusion about your problem. i would suggest you to visit a psychiatrist an give a detailed account of your routine and your problems. hope i ve been able to satisfy your query. please feel free to contact me for further needful. best of luck.