I feel you on the “welling up in tears over non-emotional issues”. I am reading a series of books with my 10 year old called My Sister is a Vampire. Seriously nothing to even get remotely emotional about and I found myself tearing up while reading to her and she was looking at me asking why a vampire feeling like a bat in a bunny hole was so sad to me when it made her giggle. I had no good answer but had to get her to read the next paragraph while I pulled it together so I could continue reading. I will definitely be reading up on the hypersensitivity topic. I wish I had some advice for you, but all I can offer is to know you are not alone.