Hi JJJ,
Sorry to hear of your health difficulties. You have been added to the samyama healing list over here: Samyama List (Healing Recipients)
Regarding your yoga practice, you obviously should be careful about any physical practice, going with the doctor’s advice, but there should not be a problem with doing deep meditation, unless you are sensitive and it aggravates your inner energies (if so, see Lessons 69 and 367). If it doesn’t, then cultivating abiding inner silence in deep meditation can make dealing with your health challenges more tolerable, and even an evolutionary step on your path. No matter what happens, in stillness it is going to be alright.
Wishing you healing, and all the best!
The guru is in you.