Water...please tell me it's gonna be ok!

How much came draining out of the underbelly? How much standing water was inside trailer and how long? If these were small amounts your problem could be relatively minor and isolated to one small area. I would not assume the absolute worst. Get it dried out and enjoy your trailer. It's not like there was a long term exposure of water to your structural members. Wet insulation can be changed out. You will not have a giant mold problem. Bleach (diluted) works for mold mitigation but you probably don't even have any and won't as long as you get it dry. Don't spray unless you have to.