I am 20 years old and i was wondering if its possible to be diagnosed with add at this age?

Less likely: But possible. Add symptoms will have been present for quite some time. Depression and other conditions can give one symptoms of inattentiveness and distractibility also. Talk with a professional.

Yes...but: There is an adult ADD, but the symptoms overlap many other issues so I am always leery of accepting the label in someone never picked up in childhood. You perform best when well rested, well nourished, healthy and in a stress free setting. To the degree any one of these are at play, you need to work through improving them first. A good checkup & discussion of your thoughts is also worth a visit.