[25] “These things I have spoken to you while I am still with you. [26] But the Helper, the Holy Spirit, whom the Father will send in my name, he will teach you all things and bring to your remembrance all that I have said to you.

(John 14:25-26 ESV)

Jesus has been talking about his impending departure, Judas' betrayal, Peter's denial. The disciples are understandably concerned - it looks like the wheels are falling off this mission. Jesus comforts them by promising the Holy Spirit.
Part 1 - help
Part 2 - family 
The Holy Spirit is the spirit of truth (v16), He is a teacher - revealing truth, teaching us about Jesus and the Father. The Holy Spirit teaches by reminding of Jesus’ words (which are the Father’s words) With a  narrow focus, this involved the inspiration of the disciples to record the gospels. With a wider focus, this is us - it is the Holy Spirit who helps us understand what we are reading when we hear God’s word. 

You might be living in a worst case scenario, without a clue what to do, but you have a teacher. The Holy Spirit can teach you in that moment by reminding and applying the good news of the gospel - God’s truth, of Jesus' words, of your forgiveness, of your adoption, of your new life.