Where can I find critism on Horace, the ancient roman writer?

Answer 1

You might want to check with the Augustan writers of Queen Anne's period (such as Alexander Pope). They felt that they were the heirs of the Roman Augustan tradition (Ovid, Horace, etc.). Criticism need not be contemporary; criticism is often synchronic. Read also The works of the Earl of Rochester

Answer 2

Check with his wife.

Answer 3

the library.