We are our worst enemies when it comes to letting our imaginations run away with “what ifs’. ☺️ So please try to relax because from what I’m seeing with your bloodwork, most of your numbers are all really good! That’s encouraging. The results are right down the middle between high and low limits. Are these your most recent blood numbers? Do you know if your platelet level was higher in January?

Because, interestingly, a B-12 deficiency can cause a high platelet level. You’ve had only 3 injections so far the B-12, so that may not be enough time to reverse the deficiency or lower the platelets. The B-12 deficiency explains many of the symptoms you’ve been experiencing.
https://www.mayoclinic.org/drugs-supplements-vitamin-b12/art-20363663
The slight elevation in the white blood count could be a normal immune response reaction considering the worsening of your celiac disease. That is an inflammatory disease and white blood cell counts can rise in the blood stream when your body is fighting inflammation or an infection. This might all be a very simple combination of those two things.
With your CRTD-D, you don’t want to take any chances with a blood clot issue though. Has there been any discussion of a being on blood thinners?