Question: what to say to friend going through separation?
Answer: I'm so sorry to hear that. ... 
Whatever you're feeling is perfectly okay*. ... 
I've been there. ... 
Have you got people you can talk to? ... 
I can recommend a counsellor if you'd like one, although I know it's not for everyone. ... 
Here, have some food. ... 
How's work? ... 
Have you watched this boxset?