So if you were starting off at a raised blood sugar of 221 (12.3), you bolused and then ate porridge and your blood sugar rose to 324 (18) that's a decent rise, but not unexpected when eating something like porridge. It does suggests that you might need to look at whether your insulin to carb ratio for bolus dosing is correct, whether you need to use a different ratio at different times of day. The first thing to do to look at that is to check what level you are at 2 hours after eating, because you might be peaking and then come back down. Pre bolusing can help to avoid/reduce the peaks.
The rise from eating porridge is really connected to what you are eating and the timing and dosage of you bolus insulin.
You shouldn't be adjusting basal insulin to deal with food. The job of the basal insulin is to keep your blood sugar stable when you aren't eating or taking bolus insulin. You might want to have a look at you basal insulin doses to look at why you are starting the day pre breakfast at 221.