Some examples of low GI whole grains: whole oats, pearled barley, brown rice, red rice, rie. Another component to consider it the glycemic load. Most fruits and veggies have a very low GL and this is likely why you don’t have the energy you had before. High GL load carbs do include many of the grains as well as things like potatoes.

Another culprit may be that you’re not supplanting the former energy source of carbs by increasing protein and essential fatty acids (EFA). Fats are a necessary macronutrient and should not be reduced too much. Proteins are often overlooked so make sure you’re getting protein in every meal.

I’d suggest not cutting out grains entirely. Also, cycling your carbs is an effective means of cutting down and managing insulin levels. Have a serving of carbs with your first meal, such as whole oats, then another serving in the afternoon, such as brown bismati rice. As you approach nighttime reduce your carbs and increase your EFA’s while maintaining protein intake, and only have low GI/GL fibrous veggies with those in the evenings as your carb.