Questions about Tehillim (Psalms)

[PlasticMan]

Recently I read about and began following the monthly schedule of saying all the Tehillim during prayer, but ever since reading 137, I find it difficult to say any of the Tehillim. I feel all the holiness of HaShem found in other Tehillim were wiped away at that moment. How can I reconcile my modern 'bleeding heart liberal' attitude and the sometimes abhorrently violent words found in the Tanakh? I try not to be judgmental, but it's difficult. I hear the same rhetoric nowadays and these particular verses seem to undermine the entire concept of HaShem being universal love.

Can you help me get my mind around this?