The physical effects of spiritual healing, or healing from any modularity,
often take time to manifest.
I've not had experience with fatigue per se, but do know it is often due to
taking on the responsibilities of others, trying to solve other peoples
difficulties. This can manifest as all sorts of issues in our own
realities. From what I know of rebirthing it is a process of getting in
touch with who we are and letting go of the energies of others.