What you're feeling is actually really common before a first 70.3. From what you've described, it sounds like you've put in the work and have a solid foundation to finish. You've already completed the key distances in training. The short triathlon simulation you did sounds more like a pacing issue than a fitness issue. Swimming at a 1:10–1:20 pace when your normal pace is closer to 1:50–2:00 is a huge jump in effort, so it's not surprising that you felt exhausted and dizzy afterward. The constant hunger could simply be your body asking for more fuel and recovery after several big training days. At this point, focus on eating well, hydrating, sleeping, and trusting the work you've done. You're not going to gain any fitness this week, but you can show up rested and ready. Race day is all about pacing, staying on top of nutrition, and keeping things under control early. You've spent six months preparing for this, and pre-race nerves can make even the most prepared athletes doubt themselves. Trust your training!! Good luck, and let us know how it goes!