HELP!! What to do?? Any experience!?

My son has had diarrhea since about Tuesday, not bad just the two times he normally has solid poop has been diarrhea. Also has been fussy, clingy, eating less, etc. everything seemed to point to teething. Wednesday evening he popped up with a BRIGHT red and raw diaper rash,(he’s only ever had ONE and it was a reaction to non toxic paint that we used to make a momento lol) seemed like because of the diarrhea but it developed very quickly. Also during his nap and bed time, I tried EVERYTHING in the book to help him with teething and nothing helped I was forced to let him cry to sleep otherwise he’d thrash violently or try to play.

Thursday he had an elevated temp (also typical for teething) then thurs afternoon he had a low grade fever of 101.4. Thursday night he was not himself at all when I got him ready for bed, limp, falling asleep while I changed him, then when it was time to go to bed he was screaming and once he had settled he was up every couple hours.

Friday morning he was burning up. Which was a 102.5 temp. I stripped him down to try and get his bottom to air out and he nursed and fell asleep for two hours after not being awake even an hour. He hovered around this temp all day and ate okay, not great but not terrible. More diarrhea and when he poops he screams immediately whereas normally you’d have to smell him to know if he pooped. He went down for his nap really easy and when he woke he was running a 103.7 temp. I gave Motrin because that’s over my comfort zone and he was clearly uncomfortable. He started to doze off in my arms around 4 which was only an hour after he had woken. He played in the evening and was fine aside from the temp for a bit then back to being clingy and fussy. Without anything else changing his temp went down tonormal within 30 minutes. He went to bed like normal then woke about 3 hours later with a 102.9 temp and has been inconsolable for 3 hours now, I don’t know what to do or how to help or if I should go to the ER. I tried calling the doctor this past evening and they never called me back which I am PISSED about. Should I call them again? Take him in? I don’t know!!!

The only things that are different are that he was around a child who was recently vaccinated (which I didn’t know until after) is it possible he caught something from the vaccine shedding? I don’t know! Other symptoms include excessive drool & grabbing at face (seem like teething but who knows). He is unvaccinated for health reasons. Ftm. He’s 16 months.