I have since learned that for me, this is difficulty with transitions combined with sensory aversion, which can be accommodated for!
For the transition, I put on a high reward podcast before even beginning to head toward the shower. Shifting from X to Y is challenging, but shifting from enjoying a podcast while X to enjoying that same podcast while Y reduces the contrast and makes it easier.
For the sensory issues, battery operated bar lights instead of the overhead light, soap that I look forward to smelling even though it costs a little more, and an IKEA folding seat in the shower (sometimes standing is hard)
This description is spot on!