Don't get discouraged!
That's where I was (and I'm sure FunnyStickMan was) at the beginning too. There's no magic pill to take that makes you capable of writing music. Just start throwing shit at the wall and see what sticks. It usually takes years of playing an instrument before you start trying to write parts for that instrument, and then years of listening and playing with other instruments to start to be able to workout multiple complimentary parts.
Absolutely. I still am not very good at writing music, but you do it one step at a time. You start off by learning other people's songs, learning how to just play. Then you goof around, come up with musical ideas. You work on those for a while, figure out what you like. Then you get an idea you want to communicate... you try to put it to words if necessary. You play with wording, rhyme, meter, simple melodies. Then you take some of the pieces and see what goes together. "Hey, this idea/lyric would really fit that music... how can I put them together?" Next thing you know, you're a composer. That's basically how you do it. No magic.