@Delticmatt100 soon you will learn the two diabetes mantras:
- " Everyone is different"
- "There are many things which affect our BG"
The second may go someway to answer your *** is going on.
The post breakfast rise may be due to
- too little insulin
- a bad night's sleep
- dawn phenomenon (might be useful to look that up)
- something on your finger which affected the reading and the 10.9 was false
And then your hypo may be caused by
- too much insulin
- an incorrect starting point due to a false reading
- exercise
- ...
We cannot always explain why our BG goes up or down. I think the important thing is to watch out for trends. If you always experience a high before lunch, you could increase your breakfast insulin dose. If it was a one off, don't stress. This thread usually blames colour of socks for a weird reading or weird day.
I have to ask - what is the "Deltic" name? Are you are railway enthusiast?