Looking back at your post, and being a vet myself (although not practicing and not trained in reptiles) - I am thinking as a postmortem - the soft lump she had may had been an abscess - maybe she ingested some substrate and that migrated through her body, eventually creating a foreign object response from her body. unfortunately the abscess grew bigger and it burst. There isn't much you could have done.
So sorry to hear of the loss. Some just weren't meant to make it.
Yes, toss everything in the viv that can't be sterilized and if you do get another reptile you can boil rocks and solid pieces of decoration with a splash of bleach added to the water, but if you can, start over fresh.
The viv should be scrubbed and scrubbed again with bleach water, then rinsed and let dry in the sun. This SHOULD kill everything bad left in the tank.