What should i do if i didn't take my once 24 hours lantus (insulin glargine) insulin?

Resuming it ASAP: Diabetes is a result of persistently high sugar over long period of time, but acutely it is much more dangerous to have too low sugar than high. So missing a dose or two of diabetic medicine is not detrimental, but should be kept to a minimum. I suggest resuming your medicine asap. Eat well, exercise regularly, take your meds as prescribed, and see doc regularly as advised. Good luck.