BG levels still dropping after 10 hours

My cat's BG levels are still dropping after I0 hours. He was 18.6 mmol this morning, was 12.3 seven hours later, two hours later was 11.2 and now one hour later is 10.8. He's due for a shot in two hours but I don't know what to do about that. he's on 2 1/2 units of prozinc and I took him lower myself without asking the vet because he was on 3 1/2 units but seemed really ill and wouldn't eat one night, but now his levels are dropping like this I've probably made it worse. He's been on 2 1/2 units since 24th November and his numbers have lowered during the day but go up in the evening, now they seem to get lower and lower these last couple of days. Should I give him any insulin at all if his levels don't rise much by the time he's due? Would greatly appreciate somebody's expert opinion. Thanks

 

@PatJ
I'd like to suggest you post in the ProZinc Forum here is the link
Sorry but without spreadsheet I am useless.
10.8 is good safe number, not to worry.
Talk about dosing for today with experienced folks over @ProZ.

 

Thanks for replying Tanya. I'll get on to the Prozinc forum. Thanks for the good advice. Appreciate it.