Songwriting - You've got the music now what
I was working with a friend that has the music and melody for a number of songs, just no lyrics. He's has guitar skill that I wished I had. He made two comments that I hear a lot, "I really want the perfect lyrics for this song," and "I don't want my lyrics to sound ____ (childish, goofy, sappy, conceited ....)." These self judgments limit songwriters more than any negative feedback they will ever receive.
The best advice I ever got was, "to write crap." To write and write a lot is the key. Get yourself out of the way. Self judgement keeps your lyrics prisoner. Almost every writing class I've been in has some variation on free writing, where you write as fast as you can, whatever pops into your mind. If you wait for the perfect phrase, you end up with a blank sheet of paper or music and no lyrics.
Another comment I heard was "that if I actually finished this song, I would have to play it for someone and expose a part of me."
No doubt about it, singing your songs for other people is a scary thing. Face it! That's what's so cool when someone shares a song they wrote.