About that first shower, place a shower chair in the tub/stall ready for your return.  Put a rubber mat on the floor. ÂÂ
If you have a wide open eye, our friends here suggest putting some goggles on or taping the eye shut. Great idea to not allow that water in.
At splash down time. Warm up the water before you enter (improve to shock value). Turn the water off momentarily. Sit down in the chair, then turn on the spray. See? no surprises!ÂÂ
On a long drive home I found a thera beads u shaped neck pillow very helpful to take the road shock off my spine and neck. We made a 115 mile trip without oops. Look straight ahead, down the horizon as you ride (you're not driving, you're riding).ÂÂ
Be good to yourself.  Let someone keep track of your meds and get doses on time for the first few days.