Crocheting grip wrong?

I've been trying to learn how to crochet, and I understand how to do it after watching some videos, but what I'm having trouble with is my grip and the stitches getting too tight. I'll get the first two chains okay, but when I try to start a magic ring, I can't get the hook through the two loops because my grip on the working yarn pulls the loop on the hook too tight to get anything through them. But if I loosen my grip on the working yarn, it slips off the hook itself. I've seriously been at this for three days and the same thing has been happening no matter what I try doing. Sorry if my explanation is complicated, but does anyone have any advice?? Thanks!