First thing I want to mention is the "3 day crash." You might feel fuzzy the first 3 days away from grain-based carbs. Hang in there, it gets better.
My best advice is to attack fat. It's real easy on a limited carb diet to undereat fat. I did this and it left me very weak. Here are some tips:
--Lean meat is not necessarily your friend. Don't shy away from the high fat meats.
--Butter is very healthy. Add it to veggies or with meats when possible.
--Olive oil is another great choice. Vinegar and olive oil dressing for your salads will add calories and fats.
--Almonds, nuts and seeds. Snack on them! Calories and fats.
--Eat your fruits and veggies. You need as muich good nutrition as possible.
--If you aren't doing strict Paleo, which you aren't, legumes might be ok. Some people with Celiacs seem to be bothered by legumes. Read this =>
Celiac and Legumes
--Remember that many dairy products have little to no lactose. Most cheeses, sour cream, etc. are almost all fat and protein. You may be able to eat these en masse.
--Bacon! Bacon! Bacon!
--Pork rinds are a great snack choice at night.
--Don't avoid skin and other organ meat if you like it.
The first 3 days on lower carbs I highly recommend you monitor your calories to make sure you are eating plenty. The real key to a satisfying low-grain based carb diet is satiety...eat when you are hungry without limitations. Snack when you feel like snacking.