"I am all that you have home."
It seems your analysis is correct to some extent:
I= Pronoun functioning as a Subject
am= linking verb functioning of course as a Main Verb
all that you have home= Nominal clause functioning as a Subject Complement
I believe that the relationship between "all" and "that you have home" is (=) In other words
"all" is equal in meaning to "that you have home"
If my assumption is correct, then "all" is a noun
"that you have at home" is an Appositive Clause
This appositive clause is analysed as follows:
You= Pronoun functioning as a Subject
have= Main Verb
at home= a prepositional phrase functioning as an Adverbial (of place)
Student or Learner