Apothecary dose

I just received my first shipment of Apothecary tirzepatide and I’m confused about the dosage. The label is different from previous. Yes , I know I should be able to figure this out so please no criticism, just please explain.

The vial 18mg, 2 ml vial. Inject .75 ml weekly. I have 6 vials.
My dose should be 12.5 and increase.
It looks to me that I only have enough for 8 weeks at this dose

18 mg total ÷ 12.5 mg per dose = 1.44 doses
So 1 full dose of 12.5 mg, with a remainder of 5.5 mg left over (not enough for a second full dose).
Concentration: 9 mg/mL
Each dose = 12.5 ÷ 9 = 1.39 mL per injection

6 vials × 18 mg = 108 mg total
108 mg ÷ 12.5 mg = 8.64 doses
So 8 full doses of 12.5 mg across 6 vials, with 8 mg remaining.
At once weekly, that’s 8 weeks of injections.​​​​​​​​​​​​​​​​