Hun, you sound like me with my first. For me... the best advice was putting everything away and winging it. I ended up not taking any birthing classes (not advised, but it worked for me), and just kind of going with the flow. However, that did lead to needing pain intervention: epidural or spinal block. Neither my hubby or I can remember which because I thought I had one, but the definition of what I experienced matched the other.
To speak to that, the epidural dosing is much milder now. They don't dope you up so much that you can't feel anything. You will still feel your contraction happening, but it won't be painful (usually. Some women still complain of pain even after). For me, I knew I was having a contraction, but I didn't have the urge to push, so I had to be instructed that it was "time", however, I knew when to push, and I could push (if that makes sense). Having said all of that, the recovery is the reason we are choosing natural this time around. I ended up needing a catheter put in because I couldn't control my urethra. That lead to quite a bit of pain during healing. Also with that, I tore during delivery, and it wasn't that bad. It itches during healing, but witch hazel takes care of that surprisingly well. But you are so excited and in gear that you don't care while they are happening
This time, I am attempting to go all natural. That has meant more preparation. I purchased "Active Labor" by Janet Balaskas, and that has been a blessing. It has taken away my aches and pains of pregnancy with the stretches it outlines, and many of those will prepare you, your mind, and your body/ligaments for labor. Even if you are not planning on going natural, it can be a super wonderful book because of the stretches and yoga poses.
I agree with the other comments: laying on your back will intensify your labor pains, and you will push longer because your sacrum isn't allowed to fully withdraw and allow the optimal space for baby's head. You don't have to go "natural" but you can still try different positions that work for you. Find what's most comfortable, and talk to your doctor about the options your place of delivery is set up for. I plan on using a squatting bar that attaches to the bed, and I have been practicing squatting from about 20 weeks or so.
No pregnancy follows a plan, and labor and delivery are the same. With my first son, my first two contractions were 5 minutes apart, and I was already 9cm dilated. Don't ask me how
I was so scared for that moment weeks prior, but when it happened, you go into mommy mode, and trust me, instinct kicks in. You will naturally move to the positions that are most comfortable. You might get on all fours and sway your hips, you might lean forward onto counters or walls and just breathe through it, you might walk and pace, you might lay on your side, you might squat, you might want a nice calming (never that hot) bath, you might bounce on a ball. Trust me... it is perfectly natural to think about everything you are thinking about right now.
If it helps, just remember that you are not alone in wondering. But also remember that your doctor is there to comfort you. Write all of your concerns and questions down and bring them to your doctor's attention. He/she will be glad to talk you through them. The other option (highly recommended) is to call your birthing center/hospital, and ask when you could come take a look around and see all the different things they offer to delivering mothers.
Oh and about the baby's head, every baby's head is funky shaped. It's the name of the game when they go through the birth canal. As far as damage go, your team will not let you push long enough to harm the child... I promise! If it came to that, you would have a C-section, and it shouldn't come to that
I hope this was helpful!!! You are not alone, hun!! Definitely look into that book, even if it doesn't spark your interest. It is a great read about how to prevent a lot of the things you are concerned about while not making you feel pressured towards delivering without drugs, like many other books on the market. There are about 50 pages of stretches and simple pregnancy-safe yoga poses to help you too!!!