As you seem to have discovered for yourself, the key to maintaining balance in the midst of our physical struggles is objectivity with respect to our emotional states. You speak of “managing my anger and sadness by willfully ignoring them until they pass”, and this suggests you’ve been able to “place” yourself as it were “above” yourself, at least for short periods of time. This is no mean accomplishment, and I cannot but admire your fortitude.
If I might suggest just a slight adjustment, however: Rather than ignoring your emotions, see whether you can simply watch them. Pushing, pushing them away, which is what “ignoring” seems to imply, might paradoxically make the anger, sadness, and other related psychological states seem stronger and more intractable than they really are; whereas by taking a kind of objective “interest” in the times of their arising, their relative degrees of strength, their connection to the course of your illness, and so forth, you may by God’s grace begin to overcome them. Of course, the feelings as such may well remain in you for some time—and we have no way of predicting how long a time this might be—but soon enough it will become apparent that they are not you, and this perception will in turn give rise to a freedom and growing sense of peace.
As for using petitionary prayers when we’re ill, we’re told on the one hand that whatever we ask “in Christ’s Name” will be granted us but on the other hand that every prayer should include the coda “Thy will be done”. In the final analysis, of course, these are two ways of saying the same thing, for someone who is truly “in” the Name cannot but will what God wills. Obviously you’re saying something very similar when you tell me: “I am confident God will take care of me no matter what, even if not in the way I prefer or would have chosen.”
Health is ambiguous. Sooner or later, everyone dies of something, and the deduction seems obvious: Our bodily states should never be regarded as more than means to a spiritual end. Prayers for physical well-being—be they for ourselves or for others—need to be offered, therefore, with the understanding that health is but a relative good. You may, and should, certainly pray that the sometimes “crippling pain” you’re experiencing not impede you in your efforts to “work out your salvation with fear and trembling”. But to pray only that there be no pain at all may be asking too much.
I realize this is a “hard saying”, but it’s nonetheless true. We simply do not know what “schedule” God may have us on, nor to what extent our salvation could not be effected were it not for our present ordeals.