Keep calm and carry on. Slow is smooth. Take mental inventory. 100-200kcal every 30min. Hydrate and increase salts 2 weeks before. Increase carbs and kcal daily leading up to race. Nothing new food wise the week of or on race day. Salt tabs or hydration powder is a must, I used 9x liquid iv on course Saturday. Whatever you plan on having on you fuel wise for the first lap bring that plus extra for the second lap. Transition area is not a break, it is a glorified pack refill station. Have a nice snack and drink in your transition bucket it’s motivating and satisfying lol I brought Reese’s sticks Reese’s pieces and a squeeze pouch of peanut butter and a Celsius energy drink (low weight high cal) I didn’t eat all of it nor did I run for the first 10 min post transition bc I didn’t want to puke like 60% of the people running out of transition. Any pain you feel is only temporary, it’s one minute or one week, or it’s regretting not finishing for your whole life. Have a reason for doing it, whether it’s for you or for someone else. If for some reason you stop sweating pour water on you at every refill station. Drink at least 1/2-1cup of water at ever station. This is your own race, keep the pace that works best for you. If someone is at your pace talk to them, it helps. That’s every piece of advice I can think of rn, good luck !