All experiences are transient; they never last. The human experience is not an exception.
No matter how healthy you keep yourself, you have no guarantee it will translate into longevity. Being healthy is its own reward in many ways, although this kind of paranoia about poison being everywhere disturbs your natural state of peace.
You say you feel powerful in spirit but do you really know what your spirit is? You say you feel you must adhere to a physical world, but do you know the physical world? Is there even a physical world?
All you are is consciousness experiencing a human body. You collect the sensory input of the body and then fashion a sense of a world. Then you start worrying about this world. When in reality, that world exists similar to a dream and while you may seem to be in it, you were never of it.
This world has never touched you. You are neither this body nor mind. You claim to be a soul having a human experience but have you made this your own understanding?
You are not an individual soul but rather the Soul itself; That which animates all things yet transcends its creations. To know the soul, which means to say for the soul to know itself, is the awakening of the spiritual way.
Awaken to yourself and this question itself will be irrelevant. It will become self-evident that you are neither this body nor its problems.
Once you have made peace with the present moment, see what happens, what you can do or choose to do, or rather what life does through you. There are three words that convey the secret of the art of living, the secret of all success and happiness: One with Life. Being one with life is being one with Now. You then realize that you don’t live your life, but life lives you. Life is the dancer and you are the dance.