Re blood sugar issues - i think those need to be discussed with medics
Re constipation - have a google for low carb chia puddings - chia seeds are packed full of fibre and absorb fluid at an incredible rate to make a gel like result. You can add all sorts of flavours ( my current favourites are coconut, peanut butter and banana flavouring chia pudding and coconut, lemon, blackcurrant and passionfruit chia pudding) -add whatever flavour you fancy, they are all high fibre and low carb as long as you dont start adding sugar / maple syrup etc