Oh my gosh, I know exactly what you are going through and what you are hearing in the middle of the night..all the cries and shrieks..
This happens to my yorkie every year this time. I usually have to start his allergy meds, Temaril P, but he is not on it the whole summer. Usually if I have bathed him too often (if I had to) or when there is a weather change he gets this reaction. Try to get Temaril from your vet, and dont wash him with shampoo next few times you bathe him, so that his oils remain on his coat. And I even had to get Reggie en e-collar this weekend beacuse he was scratching so bad he gave himself a hotspot. The ecollar is not bad at all, like a lampshade or cone is. Its this cute little "doughnut" shaped thing that he doesnt mind wearing- its like he is walking around with a little pillow
. Its so weird, he loves it! I have been coming home from work and spraying his aloe vera on, with the ecollar so he cant scratch and itch, the aloe has a chance to sink in, and he has been sleeping much better the last couple nights.
Good luck!