Diabetes: the correct dosage of insulin to get my bg to a normal level

First off, I haven't yet found the correct dosage of insulin to get my bg to a normal level. I inject Novomix 30 and started out on 10 units am/pm. I eat at regular intervals and take the insulin at the same time each day (give or take 30 mins) I exercise in moderation and eat low carb meals. I'm now up to 22 units which I've upped from 10 in increments of 2 units a week over the last few months. My bg is hovering around 130 to 220 with the occasional lows of 80 - 110. I've had a few very lows [55 - 60] and suffered the usual symptoms, sweating, shaking, confused etc. a couple of dextrose tablets got me back from outer space :)

Yesterday I had a celebratory afternoon and drank way to much beer! When I arrived home for dinner I ate a juicy steak and mixed salad (no carbs) I then remembered to test my blood... It was a shocking 320!!!!! (how bad is that? That's a question :)
Guess what...? I realized this morning that I had forgotten to take my insulin after the 320 reading the day before! Here's what's puzzling me.... When I tested this morning before breakfast my bg was 165. How can that be possible? I'm supposed to be T1 so how can by bg drop from a high of 320 to 165 in my sleep when I'm supposedly producing no insulin? Somebody please enlighten me as all this stuff is fairly new to me