Has anybody been through this?

If anyone saw my question yesterday about my son's crazy tantrums, this doesn't relate to that directly as then I was talking about how he is in general, at the moment I'm just talking about today and yesterday which is slightly different as he has both an ear infection and his molars coming through. Yesterday he screamed from the moment he woke to the moment he went to bed with the occasional 10 minute interlude and one blissful nap, and not just that but self harming awfully, his forehead is covered in little bruises and scratches from heading constantly. Today he's exactly the same, this is his first interlude of peace now and it's 3.40pm. Up until 10 minutes ago he has screamed non stop since 8am. I've had to leave the room a few times to stop myself from hitting him when he attacks me, my blood is just boiling, I know he is in pain but I am struggling to cope with this. I went to the doctors the day before yesterday (he had been quite bad for screaming then but nothing like today and yesterday) and the doc prescribed him some antibiotics for his ears and said it was the quiet limp ones he worries about, not the screaming ones. So can't go back to the doctors. I just don't know what to do. I know two days sounds like nothing but it has been literally constant. I need to go out and get stuff done but I tried taking him out yesterday and had to bring him back very quickly. I've given him calpol and teething gel but nothing is working. Stuff to chew on but again not working. It's breaking my heart that he's in so much pain. Can I do anything? I constantly have the phone out to call someone but there is just noone to call. I'm meant to be spending my first ever night apart from him on Tuesday and going to London to watch Paul McCartney, my lifelong idol, he would be staying with my grandparents but at this rate I'm going to have to cancel. Has anyone been through days of non stop screaming with a toddler? How long did it last for? How did you stay sane? Could you do anything to help them?