Good try. Let me just adjust the rulerships a bit from a traditional point of view.
You are signified by the Scorpio ASC and it's ruler Mars
If you use the 5th for the song, then Jupiter is it's significator being the traditional ruler of Pisces.
The Moon co-signfies you.
So, there we see the song, Jupiter, in the 7th house which rules the public, partners and other people. Jupiter is in it's own terms which, is not real strong but gives some weight to it. Jupiter also has a mixed mutual receptiion with Venus who rules the 7th so, the public, another person, a partner will help the song and possibly refine it a bit.
The Moon was in trine with Jupiter so, that shows you have the song which you said you did. Now the Moon applies to a square of the Sun, ruler of the 10th, your fame, recognition, etc and dispositor of Fortuna.
Saturn also opposes the Sun from the 12th and both the Moon and Sun are cadent and the Moon detrimented.....whew....that's alot of work to make the song famous right now.
I think right now you want to show-off your song to the public, play it for others, put it on YouTube for responses, get responses from them, find people who are good with music that can make comments to refine it and make it stronger. It has potential but, you need some more input on it and possible some partner who is musically inclined that can expand upon it.
best wishes