Looby well done you on your breakfast reading. It is always my worst of the day and the only way I can manage it is to have a small piece of wholemeal bread with egg or bacon. I really do not want to see anymore bacon ever again!
Lunchtime, I think you might be better off having the crisps later in the afternoon if you feel yourself going a bit low. What you could do is have the wholemeal roll with a large tuna salad to bulk things out a bit. I suspect the apple might be laden with natural sugars, and that, with the roll and the crisps might have sent your sugars up. Not sure about the coke, I've never had it so don't know what the sugar or sweetener content would be.
For your evening meal fish is great, and again, you could have a large salad or veg to bulk things out. I think the strawberries might have been the culprit, you know! I know some GD people who just avoid fruit completely and stick to veg. Alternatively, have a look for reduced sugar beans, as they might be better than normal beans.
My trick is never to sit down after eating, so I go straight from the meal table to clearing up, or some other sort of housework and try to work up a sweat. Or I go for a walk. It always helps lower my blood sugar. If I sit on the sofa after eating I always get a higher reading.
Don't be disheartened if you end up on insulin. I ate very little to begin with and it made no difference to my readings. I just needed the insulin and once I went onto insulin I found I could eat far more...I was starving pre-insulin! But try the exercise thing too.
Today I have had:
Bacon sarnie for breakfast (reading 7.7 but I went back to bed!)
Tuna mayo salad wrap with olives for lunch with a carrot and hummus dip (reading 6.4)
Jacket potato, cheese and greek salad for evening meal (reading 6.4)
I'm reading post eating again today. I do have insulin though, don't forget.