I have been very insecure about music even though multiple prophecies and always being led in that direction. I'm shy.
But when I sing, I get insecure and scared and my voice chokes, especially if I am around people.
Last year my moms friend had a vision of me being coward down but then she had a vision of be being like big time worshipper, basically.
I can't remember how that went but that was the point.
Ah... Let me encourage you with some things. I know you play the lyre, but I would begin branching out. You should pick up guitar, IMO, and pray the Lord puts better and better equipment in your hands. If you have junk instruments, this will give you an inferiority complex because you don't sound very good. But if the Lord puts better equipment in your hands, and sets a microphone up for you well, you'd be surprised how much that alone can change your impression of yourself. Your volume goes up, your voice sounds fuller with some chorus and reverb behind it, same with the instruments, and then you start to gain some confidence. Eventually you have other musicians working with you, and the better the quality of those worshipping with you, the more this builds confidence as well.
Everything builds on itself... I think prayer may be the biggest thing right now. Give yourself to really seeking God, and let Him write through you now, but continually seek Him for empowerment and better equipment along the way. I know you don't have a ton of money atm, but all things are possible with God, and you'd be amazed how much better you can sound with a $1,300 guitar as compared to some cheap thing they sell at Walmart for $69.00.
Also consider taking up keyboard, and try maybe hanging out with some Christian musicians who are using mics and a full PA system. Ask them to let you sit in on a song you know how to sing, so you can get experience knowing what it is like singing through a mic (and I mean a good one that's set well).