I see a glaring pattern is his vomiting - when you're away from him.
If you have been a SAHM for his whole life so far, it is normal for him to feel anxiety if you're suddenly away for a long period of time. He doesn't understand where you are or if you're coming back. He may be vomiting when you show up as either a release of the anxiety he'd been holding or as a way to get you to stick around. Don't underestimate kids - they are incredibly smart.
When my sister was 1, she started vomiting at bed time. My mom got really worried until she put my sister to bed one night and then watched her through the crack in the door. She was sticking her finger down her throat to make herself throw up! She knew this would get my mom back in the room. Once my mom realized the game my sister was playing, she would just go in her room, clean her up and put right back to bed. My sister quit the act a couple of days later when she realized my mom wasn't falling for it anymore.
Give your son lots of attention when you're home and after some time he will realize that you always come back. And just to be on the safe side, I agree with the other posters that you should double check what your husband is feeding him, just in case.
Good luck to you and your precious little boy!