How to write a song?

I've been writing song I can get good meanings in the lyrics. But I can't get the melody. My songs are meant to sound like Weezer, Jimmy Eat World and Sonic Youth. But I can't just come up with the melody. Help pls!

How to write a song?
if you have a piano or a gutair try fiddling around them to the lyrics, also when i write songs, i start with the melody, its easiar going backwards like that.
Reply:Those bands would sound good put together. Ummm.... Get a few friends to look at it and maybe if they play guitar or bass guitar they can help you
Reply:Just have a couple of friends look at it. All it takes is someone to hum a bar or two and you'll get it.
Reply:just write thing in your mind and start write it down then find a badass beat
Reply:It's all by chance. Keep humming melodies then you'll eventually get one that is perfect with you lyrics.
Reply:Just go over it with some friends and something will come to you
Reply:I wonder why do you say your songs "are supposed" to sound like so and so....Are you copying their style or what? Better if you just let free your inspiration!..





Another thing..It might help you...At times to create a melody, I just place my hands on the piano and play anything at random, then, all of a sudden..I have already a part of my new melody...Try that , good luck !