Your first few rows may look worse than those that follow them. I’ve found, that sometimes as I just keep going no matter how horrible it looks, I somehow get better after about 10 rows or so. Something about the weight of the project helping you a little with your tension, I don’t know, but it’s better to keep going until you finally get the hang of it, and then rip it apart and start over. Your second one will be 10 times better.
Crocheting into the back bumps can be the most annoying thing … EVER. So, make your foundation chain shorter rather than longer. Start with less than 20. It’s better for you to practice turning your work properly, than spend five days single crocheting into the back bumps of a king-sized blanket.
Finally … RELAX! And, I don’t mean, “Chill out.” I mean relax. Staying loose and relaxed with keep your stitches from being too tight. Tight stitches are really hard to work into. So loosen up that grip, and remind yourself to breath deeply.