1. The verb "am filled" is the passive form of "fill" in this sentence.
Scroll down to the chart called Passive Verb Formation, and you'll see that all tenses in passive are formed by using the past participle form of a verb plus an auxiliary verb (form of the verb "to be").
2. To indicate an error in quoted material:
Scroll down to Sic? Sic! Sic!
3. The abbreviation PS or P.S. (note that the letters should be capitalized) stands for the Latin post script: