He does refer to the unsaved being punished with eternal fire and torment; those are his exact words.
Exact words ? Citation needed.
According to Jesus’ exact words, Gehenna is the place where soul and body are kept far from God and/or are litteraly DESTROYED (so it is the opposite of “Eternal torment”) by an unquenchable fire. So the fire is unextinguishable, OK. But that doesn’t mean that unsaved suffer eternally in this fire, just that they are destroyed in this fire.
[Matthew 10:28]
…rather fear Him who is able to destroy both soul and body in Gehenna."
[Matthew 5:29]
…it is better for you that one of the parts of your body perish, than for your whole body to be thrown into Gehenna.
[Matthew 5:22]
…whoever shall say, ‘You fool,’ shall be guilty enough to go into Gehenna.
[Mark 9:43]
…It is better for you to enter life crippled, than having your two hands, to go into Gehenna into the unquenchable fire.
Some Christians think that Gehenna/Hell is a place of Eternal torment (https://www.biblestudytools.com/dictionary/gehenna/, https://www.blueletterbible.org/faq/don_stewart/don_stewart_168.cfm).
Some Christians think that it is just a place where unsaved remain separated from God for all of Eternity (https://www.gotquestions.org/Gehenna.html).
Some Christians think that Jesus never associated Gehenna with torment (https://wol.jw.org/en/wol/d/r1/lp-e/2011252).
It is so much a question of socio-historical context, of translation, of Christian tendency, of literary interpretation, and of personal interpretation, that it seems to me difficult to just pretend that “Jesus said that”.
I respect your faith and your interpretation, but it is not correct to say that those are the exact words of Jesus.