can you save another document? if yes, copy and paste everything into it and then save. check 'paste remembers layers' to help keep it organised.
if its truly not letting you do anything, you might have to work out battle plan to re-do stuff. take lots of screen grabs to help you reference when rebuilding from scratch or previous saved version after a roboot.
or you could try grouping non-image items and adding them to the CC libraries panel, that will let you 'get' them later too.
Or try copy pasting bits into in design, will lose a load of editabilitym but may be better than nothing.