Hopefully making theology simpler to understand! (2 Corinthians 1:12)

In the same way, the Spirit helps us in our weakness. We do not know what we ought to pray for, but the Spirit himself intercedes for us through wordless groans.
Romans 8:26, NIV

When you are hurting the most, feeling distraught and helpless, pray. Even if you do not feel like it.

If you struggle with what to say or even to say anything, just say Jesus. The Holy Spirit will fill in the rest.