Insulin seems to not be lowering blood glucose or just very little

Hey guys

I am in such a weird position right now that I can't understand at all and am unsure what to do.

It seems that on some days insulin works great or at least somewhat good and a few units successfully lower my bg. However, a lot of times it seems that I inject with food and the sugar just ends up being higher than before eating. So I think to myself, okay maybe it wasn't enough so I take like correction shot of 3 units when my bg is 8 and it only drops to 7... After that, it seems to slowly rise back up to 8 or even 9 again.

I thought maybe my insulin pen was bad. So I got a new one and still the same..

This is honestly so frustrating.. I am motivated to get my sugars to be as good as possible. But how can I do this when my insulin doesn't seem to be effective

Any ideas what could be causing something like this?

I use basaglar and fiasp.

Hey everyone!

First of all, thank you for your tips and no I wasn't vaccinated yet.

I thought I will answer my own question because it may be interesting to others and maybe it might help someone figure this out.
Well, I have been researching and apparently, this happens to some people with Fiasp where after using it for few weeks / few months it starts to seem more and more like you are injecting water. So just to try and see whether this is the case for me, I got a pen of Novorapid and - problem solved!

Just a couple of units with food had a great effect, got my glucose to normal ranges and it didn't rise back up.

So if anyone is having an issue like this I would suggest bringing up changing your insulin or at least trying a different one to your doctor.