The short answer is no, you can't normalise your sleeping pattern that quickly. If you've been in the habit of sleeping from 6am until 2pm your circadian rhythm (body clock) will have adjusted at least to some degree to that sleep schedule. You've effectively jet lagged yourself, and like with jet lag, you cannot adjust overnight to it. By all means try to get back to a normal sleep pattern by going to bed earlier, getting up earlier and then seeing the day through, but don't expect your body to be fully on board with that. When you're trying to fall asleep earlier your body will adjust at the rate of an hour or two a night, so expect this to take somewhere from a few days to a week to get back to comfortably sleeping normal hours. In the mean time you'll probably feel a bit rough, but that's completely normal. You've got to ride through it to get back to that normal sleep pattern. After you've done that, stick to it. When it comes to sleeping, getting enough of it is important, and the eight hours or so that you're getting is likely good enough, but it's just as important to be sleeping consistently the same hours. That regulates your circadian rhythm and has plenty of positive effects both physically and mentally. So get yourself back on track and then stick to a routine going forwards. You'll feel so much better for it.