Sick baby Advice

My 5 month old son has been fine all day until we picked his brother up from school. Shortly after we got home he started screaming as if he was in pain. I made him a bottle thinking maybe he’s just hungry. He finished his bottle but the crying began again. I checked his rectal temp and I took it out at 101.6 cus he wouldn’t stop moving and I was afraid of hurting him. I checked his forehead and his ear and they were both at 101.9 I gave him tylenol and got him to calm down a little. He gagged a few times and acted as if he was going to throw up but didn’t. He didn’t want his binky which is strange for him so I thought maybe teething but he’s taking it fine now. His temperature got down to 99.5 before it started to go back up again. It’s now sitting at 100.7. He has his pjs on and I don’t have him covered with a blanket. He is laying on the bed with me but I’m not cuddling him in fear of making his fever worse. He had tylenol at 6 but as a FTM I’m freaking out about everything. He was coughing a little. Should I call his doctor to see if I can get him in tomorrow? Should I take him in? or should I just keep watching his temp and keep giving him tylenol?

My anxiety is through the roof right now 😭😭