Blasphemy against the holy spirit is to outright deny Gods word, to cease all fear and walk in error of your own lusts against all conviction. God is very merciful to those who fear him and hope in his name.
Know that Peter himself was tormented by satan: 2 Corinthians 12:7—
By reason of the exceeding greatness of the revelations, that I should not be exalted excessively, a thorn in the flesh was given to me: a messenger of Satan to torment me, that I should not be exalted excessively. Concerning this thing, I begged the Lord three times that it might depart from me. He has said to me, “My grace is sufficient for you, for my power is made perfect in weakness.” Most gladly therefore I will rather glory in my weaknesses, that the power of Christ may rest on me.
Stick to the tachings of Jesus in Matthew chapters 5-7, stand firm that through faith in his name you have eternal life, Strive to love God and and your brothers as you love yourself, and you will gain boldness to live.