Great work on the PR!
My response may reflect others' thoughts or simply be just my own, but here are my thoughts on this:
1. I normally try to take at least 20 minutes in between snatch and clean and jerk. My ideal time is 30 minutes to somewhat mimic the wait time I'll experience in a meet. I try to establish the conditions I would for a meet at all times, so I also take my time in between warm-up lifts (usually about 3-4 minutes between each lift).
2. I normally try to get something light in nature into my system, be it some beef jerky and nuts or some other type of small snack. Your adrenaline is pumping and you're slowly expending the energy (which leads me to my next point), so you should try to get something in your system to continue burning. My thought on that is that you don't need to be under you weight class anymore (only important for weigh-in), and you're about to start the brute strength portion of the competition, so why not refuel just a little? Just as a side note, you should also try to refuel after you weigh in with the same portion.
3. I don't see adrenaline being a detrimental factor. You should be pumped that you hit a massive PR! However, don't let the excitement lead you to start your next movement too early. Sit there, talk about it, keep the excitement level up, but don't really do too much of anything. The break is intended to refresh you and get you ready for the clean and jerk. Then, use that excitement to really smash through your warm-up lifts and onto another PR lift.
I hope this helps you in some way. Again, these are just my thoughts, so I'm sure others will have different ideas to throw your way.
Javier A. Sanjuan
Olympus Barbell Club
Dear God, please help me lift heavy and be awesome. Thanks. Amen.