Like others have said, it would be very very very unlikely for you to contract rabies.
1. Your friend's dog has most likely been vaccinated against rabies. Most dogs have, since it's required by law in the U.S. If the bite had broken the skin, you would have known because dog bites tend to get infected if not immediately washed/disinfected.
2. It would be highly unlikely for your dog to get rabies from deer. First, he'd have to catch the deer (my dog has tried and never even gotten close to one). Then, the deer would have to be infected, and they are not common carriers of rabies. You should, of course, make sure your dog has had his rabies vaccine and you won't ever have to worry about him getting rabies.
3. Rabid bats don't hang out in trees dripping saliva on people. Rabid bats crawl around on the ground in broad daylight. I would be willing to bet that no one has ever gotten rabies from having bat saliva drip on them. People that get rabies from bats have been bitten by a bat.
4. Difficulty swallowing is a common manifestation of anxiety. I get it, I imagine lots of people on this forum get it. It's scary and can make you think the worse, but most of the time it's just your mind focusing too much on a body function that most people don't think about. If you've been diagnosed with GERD, that's going to make your throat sore and will probably make you focus on swallowing even more.
Honestly, the number of people who contract rabies in the U.S. is very, very small. If it was common, we would be vaccinated for rabies just like dogs and cats are. Have I ever wondered if I had rabies? Yes, recently in fact. But I was able to dismiss it because the possibility is so, so remote.