I'm very new to Zbrush and was sculpting when 'Edit Object' mode disabled (pressing T makes not difference now).
How do I fix this?

When you drag the muse does it draw another copy of your model(tool)?

If so simply draw the new copy, hit edit on that one.

You should have two tools inside the scene now. One you can orient around and the such, and another that is just an image.

To get rid of the one that isnt working go up to layers and hit clear 'layer'

You're amazing. Thank you!

No worries Glad to be of help especially since that was something that screwed me over when I was starting out