You are not alone Ryan. You have good reason to feel that way so don't deny it and push it down. It will only come back. Like Angie, we would check John's fingernails and hand for a nice pink color. At one point, he could tell when his HGB was dropping based on his coloring.
You've already mentioned some things that you can try to manage the fear/grief experienced from this illness like yoga and meditation. You may want to look at this site that can help you manage stress better. Fear is a stressor.
http://www.heartmath.org/ You don't have to buy the products. They have some books you may be able to get at the library and if you spend some time researching Heart Math, you find the simple methods they use to calm the stresses in your life.
Also, acupuncture is very helpful also. It is very good for restoring a greater sense of wellbeing.
Don't let you work be the only tool you use to distract you from your feelings.