Hi
@scaredandalone. Welcome to the Forum, and, you have come to an excellent place to get armed with knowledge, and share your experiences. You are absolutely, in the world wide web - not alone!
I can't share particular readymade meals companies with you, but I can leave that to your fellow Britishers? (Assuming that's where you are.) (or you might need to say?)
But I can share an up close and personal experience of my own with dealing with readymade meals for my mother when she was living, somewhat, lol, independently.
The company that my mother liked best, vis a vis the particular food, started doing lower carb versions, and my life changed when I went to hers to spend time with her and help look after her. (her retirement unit did not have an oven, but a couple of stove-top burners, and, the all-important microwave.)
In the lower carb versions I still took off the ever-present potatoe dish, and other higher carb food (but less of than the standard meals), and then of course I needed two of them to fill me up. So - it depends on your appetite? But they were tasty and nutritious, and did not raise my blood glucose out of range if I took out any obvious higher carb food.
I was a fan of readymade meals before I was diagnosed, as I am not really a great home cooking cook, although that should be 'was not'? Not sure! So the advent of 'keto friendly' and 'low carb' readymade meals is a wonderful additon to our lifestyle choices, as it is called. The lifestyle is also, majorly, the cost of them. But if you can afford it - I think them a marvellous thing. Just find the companies with lower carb versions of the kind of fare you like?