Following on from
@rebrascora's response, #6 above: If DP or FOTF was hitting hard then I'd expect the fp actual to rise faster than Libre - which doesn't yet know it has to predict that rise. The gap between fp and Libre would be closer or I must conclude Libre is even further adrift. So right now I'm taking this topic into detailed analysis of "what and why", which is stressful and just adding to the hassle of daily management of D, so I suggest that observation and move on.
@Ianabanani79 a tiny bit of caution here - we can overthink these things. The NHS have provided you with Libre so that your lifestyle can be improved as well as your D management and we ought to be able to help you feel comfortable with whatever Libre is telling you and then make the best use out of that data Libre is giving you. I imagine with a family of 3 teenagers there is enough going on in your world on a daily basis for you to want minimal time lost to managing D!
So I suggest ONLY fp when Libre tells you that you are very low (4 or under) or above 12 - yes above the acknowledged threshold of 10 for high. Modest periods above 10 are normal for non Ds and not particularly harmful to us; some people are sufficiently sensitive to an elevated BG and that leaves them feeling sluggish or at least different. But I think from your history you've previously had lots of time much higher and you haven't mentioned that it makes feel poorly or slowed down - so I think an hour or even 3 around 12 won't bother you.
With that start point of only fp for below 4 or above 12 relax and just trust your Libre readings for bolus doses and corrections (BG adjustments).
Alarms should be alerts.
Set the LOW Libre alert at its highest setting of 5.6 - not 4, which is too late since you are potentially and imminently going to go hypo and will be forced to stop whatever you are doing and treat that hypo.
Set the HIGH Libre alert at 11.9.
Then, strictly you just get alerts not alarms.
Trust these so you don't feel you must constantly check what Libre is saying. When I had the LibreLink app on my android phone I had to wake my phone up to get a reading, which further added to the hassle of D management.
When that 5.6 alert comes, open the app and FIRST look at the trend arrow. If that is level / horizontal then whatever change that is occurring is slow and steady, so no need to panic or even slightly overreact - just make a timely response. But its essential to monitor in case the trend turns downwards. I normally wait 10-20 mins and see where Libre is going then, if still level, have a biscuit or a frothy coffee and either of those contain enough carbs to nudge my BG back up a bit - it's not instant. Half a cereal bar, a small apple or some other preferred snack will also do - just not pure dairy with no carbs. Trial and learning will identify what works for you and is easy; we all respond differently. From this strategy you ought to be able to avoid any hypos monitoring a downward trend and increasing the snack a little (its a delicate balance to resist overreacting and then swinging up to too high; again trial and learning - unless you are really unlucky and you have abnormal and greater insulin sensitivity when low. But if you are truly T2 I think that would be most unlikely.
When high, ie above 12, either increase moderate activity (which for most of us can steadily bring about a lowering of BG), or apply a correction dose of your quick acting bolus insulin. At this stage don't try to further refine matters and start correcting because you could be going up; that level of management will come pretty naturally once you-'ve got the basics right. Have you been advised about when and what amount for bolus corrections? Are you familiar with the idea of insulin stacking and insulin on board (iob)? I'm not sure how much you already know or what courses or learning modules you have previously encountered.
Without wanting to get too tangled up in your business, have you been able to establish if you are actually T1? In England that T1 tag places us [I'm T3c, but as if T1] firmly under the more specialist Hospital D teams and ensures we have CGM. But you already do have Libre; are you under a Diabetes Specialist Team or Nurse (DSN)?
The other thing is that T2 revolves around the principle that one's natural insulin production is there, but the body is resisting that insulin. Whereas T1 is firmly about seriously declining or non-existent insulin production. From that there are consequent differences in general metabolism and how our bodies are behaving and I think that can also cascade onto interpretation of BG responses and timings (not certain about the last aspect).
Also even though I'm suggesting minimal fps, has your fp technique settled down or are you still finding them very painful? 'Cos they shouldn't be and there may be other things we can tell you to help that.
Are you still on fixed doses of basal (Abasglar) and rapid or quicker acting (Humalog) insulins? Are you now carb counting?
Sorry to bombard you with questions, but unless there is a significant medical breakthrough in the future - managing your D is with you for the foreseeable future. No hurry or necessity to reply if you don't want to.
