You should be happy that you have a diagnosis. I know you feel awful and it is overwhelming. I think most of us go through this. I found out in April and I was misearable just like you. In my case it has taken a long time to feel better. It is now 7 months later, and I have to report that I feel about 70% better, but i have more to go.
Celiac disease has a momentum to it. It does not just magically clear up, regardless of how hard you try. It may take up to a year to feel like your old self. The hardest part for me was to understand that notion. If you are constantly questioning the disease, or asking why am I not feeling better yet, you are just spinning your brain in knots. I have done plenty of this but I can now look back and say that I am feeling better. I think you will will too.
Focus on eliminating the gluten at first. Also try dairy, as that is easy to avoid and has a big impact. Not just milk, look for anything with Lactose in it. When you think you have stabilized, you can start to explore other foods. I will say that early on, you will have no way to know whether it is a certain food, celiac, lack of sleep, depression, anxiety, etc. It is hard to diagnose when the food test and results are so hard to match up with each other.
Just know that you are headed in the right direction, keep your vision on a future where you know you feel better, and you will get there.