Loosing up a stitch

I am knitting a hat in the round and my stitches are very tight and it is really hard for me to knit a stitch. I feel like I am going to break the yarn, and my hands hurt from it. How do I loosen up the stitches?? It is a thick yarn too.

You may be using needles too small for the yarn. Or you’re twisting the sts which can make them tighter to knit into. Or you’re pulling the yarn tight after you make the stitch. Don’t do this, knitting the next stitch will tighten it up.