Welcome Marie. I had to stop all my muesli and toast every morning when diagnosed pre-diabetic last year. decided to do it following advice from people here. A meal I like in a morning is one I found in a book by Dr David Cavan "Reverse your Diabetes Diet." He means keep it under control; he is not saying that everyone can literally "reverse" it. The meal is egg with courgette, red onion, aubergine, tomato and mushrooms. I have developed a liking for it although it is not everyone's cup of tea so to speak. One of my colleagues at work said it made her feel sick thinking about it.
I can also get on with about 30g of porridge with nuts and seeds but porridge is a difficult one as some people can take it, others cannot. I get on with natural yoghurt with nuts and seeds too. I also love another recipe of Dr Cavan's - what free pancakes with berries and natural yoghurt. The pancakes are made with almond flour, unsweetened almond milk and a little butter, egg, flaxseed and bicarbonate of soda. Think they may be quite calorific though so not sure if good for those trying to lose weight. I am underweight so don't have those problems.