Also, alas, things just change - often inexplicably. I suspect this is true for anyone, diabetic or not; but because of our D (if we are being diligent in monitoring our BG) we notice these changes and can let them not only disrupt our daily living but also disturb our mindset.
When you say very high, how high? What are your typical readings? Can you share a screenshot with us please?
I have from the outset,
@Busdriver60, said that it would be highly likely that your D would progress such that you would eventually need bolus insulin as well as basal. However, right now there are 3 "tools" available to you to help you push your high BG down:
Try an increase of your basal insulin. Since you have CGM you have a potentially easy way of seeing how effective this might be over several days. Don't be afraid of some experimenting. If more basal nudges you into more hypos, then pause (or have modest snacks close by to nudge you away from lows). Set your low Alarm at the highest setting of 5.6 for Libre and use that as a simple alert: if triggered have a biscuit (6-8 gms of carbs).
Exercise and activity. But I know your work at the Garden Centre must keep you naturally active and there has to be a realistic limit to how much exercise you can fit in to any 24 hrs!
Diet. Is it possible that you have allowed your carb intake to drift higher over recent days? At the very least you ought to review your meals, make a conscientious carb count and lean on your CGM to try and spot any single meal or specific food that is causing your BG to spike. If none try to push your BG down by breaking any habit: by that I mean if you have a standard breakfast try something different (low carb of course) and see if you can disrupt the daily high start.
Whatever you do, try to be systematic. Don't try all 3 "tools" simultaneously, you need to try to isolate what's going on. Also restart a dialogue with your DSN. At the very least you will be putting a marker with her that there is a problem and if this continues she will be sufficently involved to consider if you should start a rapid (= bolus) insulin.