Subsequent to uni. - i find it hard to get up (sometimes as late as 5 pm) and to go to sleep (4-8 am usually). any advice?

Sleep hygiene.: You need to get back on a schedule for sleep. To reset your sleep clock, go to bed at the same time every night, awaken at the same time every morning, don't nap during the day, use the bed for sleeping (not eating, TV watching, reading, etc), if you awaken during the night, stay in bed until your determined awakening time. Shoot for 6 to 9 hours of sleep nightly.