126 FBGL and metfomin questions

i range from 118 to 130 on FBGL with a lowish carb diet. average around 124 after a year of monitoring.

now this will sound kind of irresponsible but still i will ask anyway in all sincerity.

the low carb diet, around 100 gm to 150 gm/day leaves something to be desired. and because i exercise alot i simply need something to fill me up. its actually alot easier to to maintain FBGL without exercise cause the exercise simply leaves me hungry without eating alot of carbs.

so the questions:
if i try metformin, can i stop at any time?
and the bigger question, will metformin allow me to eat additional carbs without harm, maintaining that FBGL range hoovering around 125?