Low carb is 20 grams or lower per 24 hour period. This will put your body into ketosis and begin using stored fat as your primary fuel source.
It will be hard brother, no doubt about it, you'll be easily irritated and jittery but after 2-3 weeks you'll have so much energy you won't know why you've waited so long.
The trick is to watch for hidden carbs in everything. Soda, "sugar free" candy (which is not "free" at all and contains maltitol which if you eat more than a couple of pieces will give you the sh!ts like no tomorrow), and fruit.
Start a journal brother. That's your first step. Be honest. Start with where you are and where you want to be in 90 days.
We've got your back.