I've caught
myself doing the emotional blackmail thing a couple of times lately.
An important thing to remember is that, generally, people aren't being deliberately manipulative. They've just learnt certain habits of interaction and rarely notice them, let alone reconsider them. They're trying to fulfil needs in the way that they've habitually learnt.
It's hard not to view this behaviour as an attack upon yourself (which can lead you to respond angrily), but
they almost certainly don't intended it that way. They're just too caught up in their own pain and need to be considerate of you. (The couple of times that I've fallen into that habit recently I was feeling exhausted and desperate for help).
At your end, some inward questioning might be helpful;
why does emotional blackmail make you angry? What specifically about it irritates you? Does it feel like betrayal from someone you trusted? Does the unfairness rankle you? Do you think it reflects a low opinion of you that they'd try to use you like that? Something else?
Once you know what your 'hook' is, you're in a much better position to deal with it so that you don't get hooked any more.