That's "jestem ugotowany", which can be a nice way of saying "I am f***ed" ;)

Well... I wouldn't say that they're related. Similar, but too different.

In a way, in a context... but I don't know if it wouldn't be rather confusing (if someone got such a suggestion).

Well... "ciało" is neuter ;) "ciała" is plural.

So: "Moje ciało jest gotowe!"