Hi K.,
My heart goes out to you. I have been where you are! My son, now 22 months, always had a really hard time with teething. He got his first teeth before 4 months and he was pretty much teething from 3 months straight until about 15 months with a one month break somewhere in there. He had the red cheeks, tons of drool, and put EVERYTHING in his mouth until all this first year teeth came in by 16 months. He would chew on this hands and I tried everything under the sun to help him sleep and help the pain. I avoid using tylenol/motrin until absolutely necessary, which was maybe twice when the pain seemed really bad for him at night (when he woke up more than twice). When he woke up at night teething, I usually nursed him to ease the pain and get him back to sleep.
The teething absolutely interrupted his sleep, and along with the winter colds last year combined with the teething, he did not sleep through the night until 20 months. It was hard and tiring. He is a patient, bright, happy boy, and I also did not believe letting him cry it out while clearly teething was the right thing to do. Once all those teeth came in (it could NOT happen fast enough!), he slept SOOO much better. He had to adjust a bit once the teething pain was gone, because I think all the teething made it hard for him to learn how to fall asleep. We slowly and lovingly taught him how to get to sleep on his own. It took lots of time and patience, but it was what felt right to us.
I don't know if you are still nursing, but I have to tell you that nursing was the one thing that actually helped his teething pain tremendously. I am still nursing him and it is the magic elixir with his 2 year molars coming in (which he is handling MUCH easier than all the other ones). So, if you are nursing at all at his age, I highly recommend using that to help him get through his teething.
The end is near, fear not. Until then, continue to be the compassionate, loving Mom that you already are. They need our comfort at this young age when they are learning and growing so much and so fast.
If you have any other questions about my experience, don't hesitate to contact me.