Makes me cry, this school subject (9)
I believe the answer is:
chemistry
'school subject' is the definition.
'chemistry' can be an answer for 'subject' (chemistry is a kind of subject). I'm unsure of the 'school' bit.
'makes me cry this' is the wordplay.
'makes' indicates an anagram.
'me'+'cry'+'this'='mecrythis'
'mecrythis' is an anagram of 'CHEMISTRY'.
Can you help me to learn more?
(Other definitions for chemistry that I've seen before include "Science that deals with the properties of substances." , "Science; emotional attraction between a couple" , "Scientific study of substances - by pharmacist?" , "Science of substances and their reactions" , "The science of matter" .)