OK, here's my 2p worth on this, which will appear quite different to some of the other posts on here, but here goes.
@dan1jess2 - I was diagnosed almost exactly three years ago. My progressive blood numbers are in my signature, so I won't repeat them on here. As you can see my numbers have changes quite a bit and stayed changed, without any medication. Now I will state right up front that as well as working hard on it, I have been very lucky in that my body appears to have been able to repair itself and to almost reset itself to react differently, in a positive way, to some of the things I eat and drink. Not everyone's body can achieve that repair, but a good number can.
My numbers through the day (and night) are usually very low, and I spend a lot of my time in the very low 4, an almost equally similar amount of time in the mid-high 3s and a bit of time in the low 3s, with some 2s thrown in. I don't have any hypo feelings at all, although when I get down into the 2s, it's usually as a meal is cooking and I'm hungry, so I can be prowling around the kitchen/cooker/ cook (often my OH) waiting to eat.
If I do feel a bit off, I just have a cup of tea, with some milk. That just brings me up enough to make me feel a bit more comfortable and it means I don't go nibbling.
I like to think my body is now behaving (as far as my blood numbers go anyway), pretty much like a non-diabetic person. There have been few studies done on non-diabetic people and their blood sugar activity (why would anyone want to invest a lot of money in something that doesn't need fixing?), so there's limited information out there, but I believe, from stuff I have read, that non-diabetics bloods do vary, and can go low, but their bodies kick in to buoy up their blood numbers, until they eat again.
However, enough about me, and onto you.
As I understand you are only taking metformin (not insulin or the like), it is unusual for medically worrying hypos to occur only on metformin. Sometimes as our numbers start to come down, from running "higher", our bodies object. They like to run in a comfort zone, and it looks like your comfort zone starts around the mid-4s. Going below it is very unlikely to do you any harm.
Of course, why go low after breakfast could be a number of things.
It could be that what you are having for brekkers is giving you a bit of a spike, then a drop, and if the drop is relatively quick, it can feel uncomfortable. If you're having cereal/museli or toast based breakfasts, I would wonder if that was the case. In most T2s those foods can be tricky in the mornings, when insulin resistance can be higher than later in the day.
If you are having that sort of breakfast, I might be inclined to think about seeing what happens if you try something like some eggs (scrambled, boiled, whatever), with our without some scrumptious bacon and see if that changes anything. Those sorts of brekkers can lead to a lower rise (which often discourages the sharpish drop), and also helps us stay feeling fuller for longer.
Or secondly, if you are having a less carby brekkers, it could be worth maybe just increasing the portion a little and see if just plain old eating a little more helps?
Personally, I have never snacked, or eaten between meals. I'd just get fed up of all that eating, but that's peculiar old me. I'd rather try to modify my meals to keep me steadier in between.
Perhaps it could be useful trying to have something simple like a cup of tea, with milk, when you first begin feeling a bot "off", and see if that just takes you "off bottom", until your next meal.
In any case, I would be avoiding Dextrose tablets like the proverbial plague. To me, they taste vile! I'd be more interested in exploring the root cause of the issue, rather than "treating" they symptom.
Good luck with it all. feeling rough, regularly, isn't good, for sure.