I've found that eating gluten-free products doesn't make much of a difference in my symptoms & I haven't tried the SCD...yet.
As for the whole carbs thing, I have found that I can keeep down(and they don't go through me) carbs better than most other foods. Crackers, plain cookies, chex mix, rice cakes and sthings like that have really helped my GI symptoms. Of course, I can't live off of things like those but I find they don't aggravate my intestines as much as some other foods like hamburgers and onion rings. Everyone is different though. I can handle eating a burger with fries one day and try it again the next and be crying in a fetal position for hours...For me, it is all kind of a trial and error process but for the most part carbs=good.
Nutrionally speaking, I like to drink a lot of vitamin waters, ensure, and try to find ways to add protein in my diet through things like eating lean meats, peanut butter crackers etc. I'm trying to maintain my weight as well. The weight will come back eventually when you get treatment hopefully. I've lost over 85 pounds since February & I still can't wrap my mind around it all...
I never had a problem with lactose until I got diagnosed with Crohn's. I love dairy so much but I try to limit it and take lactade(sp?) when I am really craving something like a milkshake and that helps. Fiber & I are kinda iffy. I do it in moderation.
Good luck with getting a dx and treatment YP9! 