Welcome to the world of EARLY teethers! My little girl did the same thing with all her teeth. The molars took FOREVER to actually break all the way through the skin. (By 13 months.) It took her at least a month of teething before they were in all the way. But the first few days and the last few days were the worst. She seemed to be okay in the middle of that month. The canines (cuspids) were also VERY early, and seemed to hurt even worse. The only thing that really helped her was Motrin and very cold drinks. I even froze her first birthday cake in strips and she ate those frozen. It seemed to help.
The good news is, once all the teeth are in early, you are done! By 16 months, we were effectively done with teething. (At least 'til those 2 year/second molars come in sometime between 20 and 30 months.)
By the way, if my DD got sick while she was teething, the tooth would STOP until she was better. It seemed like her body thought getting well was more important, so it would put the tooth on the back-burner, even mid-stream.
It could be the immunizations in combination with his teething are causing the misery. Hang in there!
Wish I had more help to offer.