If I never feel the Holy Spirit’s conviction, could it be because I’ve committed the unforgivable sin?

What Is the Unforgivable Sin? Read here: https://www.jw.org/finder?wtlocale=E&docid=502016103&srcid=share

I don't think you're a Christian. Did you peel the potatoes?
the Holy Spirit is given by God to those people who convert to Him!
It is clear that if a Christian person distances himself from God by committing sins, the Holy Spirit withdraws from that Christian!

Blasphemy against the Holy Spirit can be forgiven if the person asks God for forgiveness, and is converted to Him!

The only unforgiveable sin is rejection of the Son Jesus and without Jesus you have no hope of receiving the Holy Spirit.  It is the Holy Spirit that teaches us all things concerning Christ; brings Scripture to remembrance when we need it, because the word of God is a powerful tool and it is the Holy Spirit that gets us ready to meet the Lord.

Read Mt. 12 and Mk. 3 for the impossibility that anyone can commit the "unforgivable sin" today.  Pharisees accused Jesus of driving out unclean spirits by the power of Beelzebub.  Therefore that event cannot be duplicated and neither can that sin be duplicated.

If you never feel the Holy Spirit’s conviction it's because it doesn't exist. It's just a silly fable.