Old lady with a question

I currently have Comcast for my TV, Internet and Phone.  The monthly bills are KILLING  ME.  I keep hearing about Netflix and Hulu and Roku.  Can I "divorce" Comcast and use one of those services instead of Comcast?  Or does Comcast have an exclusivity agreement with Livermore as I am told by friends thereby forcing us all to pay Comcast outrageous pricing to have phone, internet and cable TV???