Sounds hilarious. Must be the interchange of a regular "o" and a nasalized one.
becauseafter "jest/jestem/jesteś..." you use instrumental case. You only use nominative for adjective without noun, for personal nouns (jestem Ian) or when you use "to", but you can use "to" only in "noun is noun" sentences.,
'ci' isn't pronounced as English 'ch', but for many people it's the closest they can pronounce, at least at the beginning. "ć" is like palatalized 't'.
There definitely isn't any m, if the word ends with a vovel then it really is pronounced as a vovel.
"ciocia" is the basic, Nominative form, but here you have Instrumental: 'ciocią'. Ą is nasalized O. Imagine the 'o' in 'rose', but rather a bit slighter.