If you are having frequent hypo's then you need to look at the insulin you'll injecting...
It sounds as though you need to check if your background insulin is correct, easiest way of doing this is a fasting test (do remember to have plenty of hypo kit and test strips, and abort if you need to treat a hypo or high)
If your background insulin is correct, hold steady +/- 2mmol/l levels then you need to look at your insulin-carb ratio's as it's likely that these may need adjusting, or you may need to adjust your dose to the exercise you are going to do!
When treating hypo's, use fast acting carbs first get your levels up then use a slower carb to keep the blood stready..
Edit,
Just clocked you'll a T2 diabetic, the above only really applies if you'll using insulin, but if you are using other oral medication, then you need to get hold of your GP to discuss these hypo's, and it may be that your oral medication needs reducing...
Hopefully another T2 will now come along and bail me out with some more helpful information
If you hate the cereal bar before your hypo was fully treated, it will slow down the effect of the full fat coke you had.. Taking longer for the blood glucose levels to return to normal, which then leaves to over treatment and a rebound high.. As you retreat the hypo thinking that you need more to treat it!