Hi first thing is don’t be afraid, I actually went the other way from Lanctus to Levimir , I was on 28 units of Lanctus but then took 14 units of Levimir am and pm , so your figures sounds reasonable. Lanctus lasts a lot longer than Levimir so you take one at night , it kicks in in the morning and helps give you a “ base level “ of insulin through the day while your awake ,
It’s worth increasing your testing for a while just to see how your body is with the new insulin , I’m sure it’ll be fine with nothing to worry about ,
Stay safe take care