Learn English – As if I am/I were/I was

conditional-constructionsusage

When forming a conditional clause with "if", when should I choose "if I am", instead of "if I were" or "if I was"?

I think was is never correct, but may be acceptable for informal use.

I'm writing a song lyric:

If, after life, I satisfy myself for feeling more alive,

will I still feel alive as if I'm breathing?"

Am I correct for choosing "as if I am"? Would "as if I were breathing" be better?

I am
I am ten pounds heavier now.

you are something now

I were
If I Were A Rich Man

if you were hypothetically something

I was
I was 10 pounds lighter in my twenties.

you were something in the past

For your lyrics

as if I was breathing
as if I were breathing

could both be used depending on what you are trying to say.