Hi KermodeMamma, like GrumpyGramma said, a lot of us have had this problem. When I first started I knitted so tight that if I used wood needles I could barely budge the yarn. So I switched to aluminum. Also, like GrumpyGramma said, practice practice practice. I bought a big ole thing of the cheapest yarn I could find and first did only knit stitch, then purl, then knit and purl...soon I was knitting much smoother and not so tight. I almost gave up, too. But once you find your groove it's so fun and gratifying.
Also, if you knit Continental, maybe try English. Or vise versa. Maybe? I hope it helps. We don't want you to give up. Just find your grove and you'll totally be a pro