What is insulin like...?

I was diagnosed on Monday, 7/7/2014, and put straight on to Insulin on the Tuesday.
So all a bit of a shock and still to really sink in.
Now Wednesday, and getting the hang of it after 1 day of injecting, Still a bit apprehensive each time though. BG is still up and down, from 9, up to 15, so hoping it will settle down eventually.
Just a bit of an ache on the left side of stomach, was going to do the left side one week and the right the next to give each a rest, not sure if this is the best way. What do others do?

I have a monitor to test for ketones - T1s can get ketones, usually if you don't inject your insulin or if you are ill. I have a different monitor for glucose as I like my FreeStyle InsuLinx - it has a calculator to help with insulin dosage and has some pretty cool software to help keep on me on track.