@jlm - The harsh reality is that Gliclazide is a more powerful drug, in terms of reducing blood sugars than Metformin.
As has been said, Gliclazide stimulates your pancreas to push out more insulin. but unfortunately Gliclazide is also known to adversely impact on weight control for some people.
Metformin, on the other hand, to put it as simply as I can, helps your body deal with your natural insulin more efficiently. It is also known to reduce the appetite in some who take it, which can positively impact in weight control.
In essence by stopping Gliclazide you have taken away the downward push on your blood scores. In your case, then adding in additional carbs (which irrespective of their GI scores) tend to push the blood numbers up. It is indeed a bit of an unfortunate change combo, and to an extent it is understandable that your numbers might have crept up a bit. It does also take some people's bodies a little while to be used to any changed eating patterns; whether what's being eaten, or when.
As I suggested in another thread, I'd seriously consider deciding which of your two changes you will follow and seriously consider deferring the other, until you learn the impact of one change.
Your comment about animal protein impacting triglycerides is one often heard, however, my personal research (including various consultations with Dr Google) lead me to believe that triglycerides are far more impacted by carbs than fats or animal protein.
Some people find that in the earlier phases of reducing carbs, their cholesterol numbers rise a bit, but this tends to be a transient phase, with a longer term shift to improved cholesterol. The infuriating aspect, though, is that what happens for most people isn't guaranteed for everyone. Oh, if only it was that simple!
So, my nudge would be choose one of your changes, and stick with it. Have bloods done as regularly as your practice will tolerate. They do seem to be joining you in your efforts to improve your lot, which is fantastic.
You'll get there jlm, but please be patient with your body. It's important that you understand what you're doing, and why. For me, that understanding really keeps me on-track when I have a grumpy, hate it all day. I'm sure we've all had them at some time.