I wanted to know what part of speech a phoneme might be or I wanted to know if a phoneme might be a part of speech and I wanted to know if a phoneme can be an affix. I also wanted to know what a phoneme might be if it isn't a part of speech or an affix.
"Part of speech" is usually interpreted as a technical term, referring to a classification of words, based on similarities in syntax, for example "cat, house, bear, truth" are nouns because they can be subjects. Traditionally, this refers to noun, verb, adjective, adverb, pronoun, preposition, postposition, conjunction, interjection, numeral, article, and determiner. These can be expanded to include clitics, auxiliaries, negation and so on. Subparts of words, such as -able, -un-, -ity are not generally assigned a "part of speech" since they are not words, they are affixes that form words.
"Phonemes" are not "parts of speech" in the traditional grammar sense, because they are the things from which are constructed, but they are not themselves words, and their distribution is not governed by syntax. They are components of speech, to be sure, but being a part (component) of speech is not all there is to being a "part of speech".
An affix can be composed of one of more phonemes (I will omit the peculiar case where an affix is composed of less that a phoneme). You could say that phonemes are the minimal building blocks from which morphemes (roots and affixes) are constructed, though phonemes are themselves built of smaller bits. A phoneme is roughly like a molecule, and a morpheme is like a cell. A sentence is like an entire dog.