Hi. I normally just read the forums but having coeliac disease and type 1 diabetes for 30+ years I have had my fair share of bread issues. I don't live in the UK anymore although do visit often but I now make my own bread and use lidl's gluten free bread mix - comes in both white and brown, it's the cheapest bread mix as far as I know and if you use unsweetened fizzy water you will get results almost as good as normal bakery bread. I also add flaxseed, and sunflower seeds as my preference and add extra leavening agents , great eaten on the day its made - otherwise cut when cold and freeze. Best not to refrigerate gf homemade bread as it will dry out easily. I also make Japanese milk bread, keto coconut bread, quinoa almond bread, pumpkin and ginger, and curry bread all gluten free.
My preferred brand loaf was always The Juvela Long Life Fibre Sliced Loaf but only available on bulk prescription (needed to get 8 loaves each time). If you want a bread that doesn't crumble look for xanthum gum or psyllium seed husks in the ingredients. I agree with TriciaWs all gf bread is best lightly toasted.
As a total substitute for bread you can try keto waffles as a change from bread just depends what you prefer. I don't do keto but have made waffles from bananna/egg or buckwheat flour or gluten free oats. Hope this gives you some ideas.