Leaving my breastfeeding toddler for 3 days...

Maybe this is more of a vent than anything, but advice from anyone who's done this would be appreciated. I have to go away for a 3 day business trip and there is no way my 2 year old can go along this time. I haven't pumped for a year and half (when he turned 1) and he drinks regular milk and eats food just fine. However, he still nurses anywhere from 1-4 times per day for comfort, and often 1-2 times at night.

I tried to pump at work on Friday and got absolutely nothing. I still feel a minor let down, he sucks/swallows, and I can see that he is definitely getting some milk when he nurses, but I'm freaking out that I will be unable to pump and wind up with mastitis while I'm away.

I'm also really concerned about how he will handle it emotionally. He's breaking my heart because we've briefly discussed me leaving and he says, "you leave and I will be sad" then cries. I also recall reading a story from a dad with a breastfed 15 month old, talking about his wife was gone for a few days, and he had to keep the kid away from the garage because he would get hysterical at the sight of the mom's car.

Please tell me it's gonna be OK... :(