It would depend on your style. If it was pop music, I'd say you're pretty far off, especially when you're landing and operating between notes as a center. But for the type of music you're doing, is there a reason to worry?

But it can also help you when dissecting your way to knowing what you sing and how you sing. Why not use this to solidify your melody. Is it supposed to be a B or a C? That's something you ought to know. Is it an F# or a G? Of course in Am it should be F or G. Though over an F chord, I'm thinking it ought not be G...

Use it to know your notes, then play your melody in to a keyboard or on guitar and sing to that. Eventually you'll get better at your melodies and tighter with your pitch on your singing.

Jody Whitesides
A Funky Audio Lap Dance For Your Ears!
www.jodywhitesides.com