I need you to listen carefully to me.
If you are scared to death that you have committed the "unforgivable sin" - then the odds are great that you have NOT.
What was Jesus talking about when he said that blasphemy of the Holy Spirit will not be forgiven?
Jesus had been healing people. Some scribes came along and said that Jesus had the ability to heal people because he was possessed by the devil - that he had an "unclean spirit". Mark 3.
Jesus didn't have an unclean spirit - he had the HOLY SPIRIT! These men had attributed to the devil what was really God's power. They showed COMPLETE contempt to the God they claimed to serve and taught that Jesus was a devil. They believed it in their hearts and spoke it to the people.
Do you believe that Jesus is a devil - do you actually believe this in your heart? Do you believe in your heart that the Holy Spirit is a devil? Do you speak this and teach it to others? If not, then you have NOT committed anything unpardonable.
Ultimately, the blasphemy of the Holy Spirit is the rejection of Jesus Christ as Lord and Savior.
I know people who suffer from various mental illnesses and suffer from "intrusive thoughts". These are thoughts that randomly pop in ones head and they may be benign or they may be profoundly ugly.
If you have surrendered your life to the Lord Jesus Christ, then when these ideas or thoughts pop into your head - reject them in the name of Jesus.
God knows when we suffer and does not hold things such as this that we cannot control against us.
The more you dwell on intrusive thoughts and try to fight them and worry sick that you are somehow branded as evil for them, the more they stay because YOU are clinging to them and ergo, the more tortured you are. Intrusive thoughts of any kind should go in one ear and out the other. Whisper the name of Jesus instead of trying to fight a battle that is tormenting you. Don't attach your spiritual growth, salvation, and worth to God to those thoughts. That's what the devil wants you to do. That way - you feel worthless, unloved by God, and miserable.
And when you get to that point - THEN you feel like God isn't helping you and that Christ isn't listening to you and then you get really, really scared and miserable.
Focus on something else and ask God for help when this happens. It takes work and time, but success will come. Allow thoughts such as this that invade your mind to become impotent and pathetic.
And remember - FAITH stares down anything. Cling to Jesus. I will pray for you.