Is my sleeping pattern considered normal/acceptable?No! It is neither normal nor acceptable. I think you can decide this in better way for yourself by just assessing how do you feel throught out the day. This sleeping pattern can affect your metabolism in a long run and it may make you feel stressed. again as you grow , you will have more responsibility and at one stage you require balance between your personal and professional life , which will be very difficult to achieve with this sleeping pattern. hope following links will help you
I feel sleepy and have fatigue during the day off despite of 6 hours of sleep
7 Health Consequences Of Going To Bed Past Midnight
I will tell you what really has helped me out with sleep. Acupuncture. If you live in the states there are various "community acupunture" clinics throughout. This means you pay between $15-30 a session ( you choose what to pay on that sliding scale ) and treatment is not nearly as expensive as going to a doctor ( $ 50 a session ).
You have to go consistently as certain points in your body get blocked again and acupuncture helps to unblock those vital points.
Sounds like a college sleep schedule. If you feel healthy and you're taking care of business, as you should, you got no worries.