What is a more proper way to say, “You are your self first supporter”?

"self first" uses two words to modify "supporter." The words must be grouped by using quotation marks. (Most, if not all, compound adjectives are grouped by using a hyphen.)

You are your "self first" supporter.

I've found that making a sentence simpler works best. In your case, try:

I support myself first.
    -or-
Tom supports himself first.

etc.

What is a more proper way to say, “You are your self first supporter”?

"self first" uses two words to modify "supporter." The words must be grouped by using quotation marks. (Most, if not all, compound adjectives are grouped by using a hyphen.)

You are your "self first" supporter.

I've found that making a sentence simpler works best. In your case, try:

I support myself first.

or

Tom supports himself first.

etc.