It must be difficult for you to keep proper track of what your body is doing if you only take one reading a day. It's a bit hit and miss!
Could you, for a while at least, take a reading once before and twice after each meal (at 1hr and 2hrs) and make a note of what you ate and the associated readings? That way you'd know specifically how various foods affect you and you could decide what you can keep or must ditch.
Just a suggestion! There's probably lots you can do before upping your medication. If you post an example of a day's food and the readings, there's loads of people here who would help you sort it out.
Don't give up!
DG