I see you're on diet only. Porridge at night would probably not be great. High in carbs, it would probably give you even higher BGs at night leading to even more getting up to the loo. A lot of T2s can't even tolerate porridge for breakfast.
Can't comment on the menopause, but the loo symptoms are typical of BGs being too high at night.
What sort of diet are you on? Give us a typical day's food and we might be able to help you.
One thing that helped me at night was to eat NOTHING within 2 hours of going to bed, and to do a 10 minute hard exercise session about an hour after my evening meal. Gets the BGs down quicker and further. I use a trainer machine, but you could go up and down stairs, or a brisk walk, or anything that's within your means.