Here is a link to a video by Sarah Joy with tips to rid yourself if the screeching cello sound. I am struggling horribly with and have revisited this video for further encouragement.

Sarah Joy, Cello Bowing (Eliminate the Screech)

I wish I could get the smooth soothing cello sound I so dearly strive for, even more than intonation! The screeching disappoints me more than off intonation. 

So, here is a link that may help, or at least encourage you to put more effort into it,

Sarah Joy has many cello videos, all of which are escellent.