You don't want to know the worst parts! You will get through it! Especially if you want to be a Marine. I have worked with some Marines, and they had some stories. . . But the training is designed to keep you ALIVE. To instill in you a sense of self-confidence, so that, even if your entire platoon is wiped out, you will persevere and complete the mission. There is no such thing as failure. You will come to believe that you are Wonder Woman, Superman, and Spiderman all wrapped up in one. And you will also learn to trust your fellow Marines with your life. Please do not psyche yourself out with fears.
I know this does not answer your question. I was a career police officer, and being a female in a male's world, quickly learned not to show fear or weakness. I was never in the military. Hopefully someone else will answer this question for you.