Hi
I think glucophage is metformin? and if so then taking it later on its own could cause the bowel problems to worsen, I can't take it except right in the middle of a meal.
I suffer very much from DP too,I tried everything that was suggested - including cinnemon, milk thistle, chia seeds, eating certain foods before bed, cider vinegar, but nothing worked. I would go to bed in the 5's wake up with a BG of 6's it would rise before breakfast to 7+ then after my toast it would rise to as high as 12 and stay there until after lunch.
I found that if I eliminate carbs completely in the AM then this helps , It will still rise from 5 at bedtime 6 and then to 7 by breakfast, but a non carb cooked breakfast seem to 'switch off' the further rise, my body just behaves like after any other meal I may rise to 8 but then come down again and by lunchtime will be back to 6 's again.
I also found that if I had had a carby meal for tea the night before, then it tended to be higher and more stubborn the next morning.
Good luck with the search for a solution.