Write, I feel for you. I know that in my life, physical manifestations of really negative emotions usually came to me after the fact...as if my body were waiting to fall apart.
This may sound VERY strange, so take it with a grain of salt, but there are connections between what the mind does and what the body does that are hard to pin down. Perhaps, as you acknowledged, this is a time of no big stress, and what your body and mind have done for so long, as a pattern, IS deal with stress. So it might be creating stress as part of this pattern. In a spiritual sense, perhaps this is another lesson to become aware of. Your possible pattern of needing to have something go "wrong"... and in my situation, I found this to be based on my underlying beliefs about unworthiness. Food for thought anyway.
My fiance has a chronic illness...nothing has touched it, really. It isn't debilitating, and he functions fine, but it is always there and sometimes very painful. We have some lively discussions about the mind/body connection, let me tell you. I am not certain of all of this, as it would be a stretch for me to think my friend who just came out the other side of a bone marrow transplant actually CHOSE cancer for herself...... so like I said, musings for a Saturday.
And I have decided, in my own "healing" that blessings are not only bestowed by men in dresses

So I will send you my own blessings for good health!!And you might consider a bunch of funny films as therapy....laughing always helps anything.