No matter how I type this, it sounds wrong but I don't mean to disparage anyone or imply I'm better than anyone, so here goes! What helped me get through MEPS and Basic Training was that I looked around and found a few individuals in equal or worse shape than I (mentally and physically) and just told myself that if they could make it, I could make it. They made it and guess what, so did I, and so will you. The DI's job is to help you make it, not try to make you fail. Yes, they need to weed out those who can't do the job but very few will be sent home. If you are at least of average physical shape and intelligence they will give you the training and tools you need to do the job. Don't worry, you'll be fine. Best advice, get as far through training as you can without your DI learning your name, it's the showboats and know it alls that the DI's come down on. Good luck.
rkanjl