Hello and welcome.
So pleased you got a meter. This will tell you where you are going wrong and is the best tool you can have. Testing before a meal then 2 hours after will show you what that meal has done to your levels.
Porridge is not for everyone. Some people can manage, but others can't. Try testing before and after porridge and see what it does to you. Same with the other meals you are normally eating. If the rise is much more than 2mmol/l there is a carb element in that meal that needs reducing in portion size, or even avoiding completely for a while.