At my wit's end!

I am so tired and frustrated right now. I am typing this as I lay next to my son (18 months) who has been whining, coughing, scratching his hands and head as if he's digging for gold. Allow me to break things down. He developed a cough a little over 2 months ago along with a runny nose that won't seem to go away. I asked his pedi about it and he didn't seem concerned with finding out why. ok. Took him to urgent care later that same week because he developed a fever. At this point he had the cough and runny nose for over 2 weeks. They told me he had allergies and the fever was possibly related to a developing ear infection. They prescribed him allergy medication and antibiotics. The allergy medicine helped a little with his runny nose and he coughed a little less. However it never went away completely. You can hear the fluid and mucus in his chest when he breathes and the congestion in his nose. "Normally" he would cough at random times during the day and whenever he sneezed. Not much and at times he would go the whole day without coughing until at night. Today he has been coughing non stop and the runny nose is on full blast. Idk what to do at this point. The allergy medicine isn't working anymore and I'm honestly not even sure it's allergy related. on top of that he started throwing up more so than usual friday and Saturday and he spit up some today. Along with frequent loose and watery stool. I honestly dont know what to do. he has a doc appointment next Monday but I'm very concerned. I feel like there is nothing I can do 😔 i honestly want to take him back to the doctor or a children's hospital and demand they figure out what's wrong with him but I just started a new job and can't really can in to work without risking losing the job.