First of all, I would ask you if you're very interested in the subject you are studying? If it's your first year, chances you are doing all your GEs and some of them can be hard and boring as hell. If it is a boring class, chances are your memory isn't to blame, because everyone reads and remembers boring stuff poorly. I speak from experience. After being a straight A student in high school, I went to one of the top 20 schools in the nation, only to realize I was failing after a year or so going there. I couldn't wake up for classes, I slept in most of the day, I couldn't pay attention, etc. For a student who prized himself based upon grades, I wasn't feeling great about myself. Luckily I found out about the student psychological services. Turns out I was suffering from a mild depression and ADD. ADD? How could that be possible, I'd been a straight A student and never ran around the classroom, though I did like to blurt comments out at my teachers when I felt so inspired. I was suffering from ADD, inattentive (daydreamer) non hyperactive type. The depression stemmed from my poor performance in school. I was given different meds for the ADD until we finally found one that worked, and I took it for about a year to get on track. Now, to the point, I ended up in the most awesome major- Cognitive Science. I found it insane and awesome all at once, it engaged my brain, I loved going to school then! I was able to stop taking the meds altogether because the material enthralled me that much! I've been able to stay off the meds for 9 years altogether because the material was that interesting.
Two points- get yourself checked out at the school student psych services center. You may be suffering from depression, ADD, Insomnia, any other myriad of conditions they might be able to help with, sometimes just with techniques and not pills. Secondly, find a major you love not one you think that will love you in turns of money.
Good luck.