Yep a sleep training question

So my girl always puts herself to sleep no problem, she slept through for about a week and now wakes at 1:30am and 5am, she cries and cries and cries, I try leaving her to it, try putting the dummy in but end up just feeding her. Or some nights I'm so tired to just automatically feed her.

How do you sleep train in the middle of the night when you are so tried?