i think if i was is grammatically incorrect if preceded the article "a" or a noun
if you want to follow it with a noun, use were instead
but if you were to use a verb or an adjective "if i was is correct"
example:
if i was chosen to be next, i'd be glad
if i were a boy, i'll court you
If I was loved by you, i'd be the happiest girl in town lol