The sum of all that Jesus’ death meant to Him was joy! The path to that eternal joy led through suffering. Having triumphed over death, Jesus has returned to the glory that He had from all eternity in heaven at the Father’s right hand. There He received forever the unceasing and undiminishing praise of the Living creatures and the elders as seen in Revelations 4:11.
Jesus wanted the disciples to understand, that us through them, that He was not leaving them for no reason, but because he was leaving them, they would be stronger, and have a better grasp on the things that He had taught them.
If you truly find yourself struggling to know peace, and understand truth, perhaps it is because you have no true relationship with God through Christ. Maybe it is time for you to come to a proper understanding of that relationship offered to you through Jesus Christ.