There are a bunch of ways to get around that, I know exactly the wall you have hit. Here are a couple:
1) Go look up a ton of old Beatles songs. Figure out the key they are in, notice the pattern of what chords are in the verse (ex: 1 and 4) and what chords are in the chorus (ex 4, 5, and 7). Start with "Let it Be" for a good example of how to use the same chords in a different order. Also check out the Bare Naked Ladies "The Old Apartment".
2) An easy way is to use the 1 and 4 in the verse and the 4, 5 and 6 in the chorus.
3) I sometimes use the second or third chord in a verse as a jumping off to the chorus.
The one thing I have found is the more I learn about music theory the more I can write. It's not so much to more esoteric stuff but the simple structure behind the music you hear everyday. If you find a riff or a chord progression that sounds good to you, go find out how to play it then spend some time figuring out the key and which notes the artist used. Think to yourself "how does that work?" and go from there.
Isn't this great?