Dear MaryJane,
Do not give in to fear, everything is for the glory of Jesus. Imagine the opportunities to witness that will come through just the additional testing process. Most times, in our daily lives we are isolated from other people, When sitting and waiting for medical tests you are offered the chance to interact with people who are undergoing the same stress you are - but without the benefit of Jesus Holy Spirit living within them. How lonely they must be.
Being filled with His Spirit, submitting to Him in everything, He will be able to reach to them through you. (Please understand, it is the Spirit of God who does the work through you. This is not work for you to do, you are just the branch - Jesus is the vine.)
Through this experience you are serving Him, you have nothing to fear while in His service (it is all covered in the job description). Even if the diagnoses is bad there is much that can be done in treatment and I doubt any suffering involved can be anywhere as painful as crucifixion an revilement by the people you came to save.
I know you can get through this because I know Him. You and I have the same Holy Spirit within us, this is how Saints know one another. Praise Jesus and in everything give thanks, I do pray for you,
white stone