Recently I have been having many blasphemous thoughts. I have repeatedly cursed the Holy Spirit. This makes me very scared and worried about my salvation. Supported by my family and friends, I have repented. However, I am still afraid. I don't know what to do. I feel that my relationship with God is being destroyed.
A person cannot repent without the work of the Holy Spirit in him. The fact that you have repented; and are worried about your salvation is the absolute proof that the Holy Spirit is working in you and reproving you. Do not overcome one sin to fall into another. To be afraid and feel hopeless is not God's commandment. God is merciful and He knows the heart of everyone. He knows how much you love Him. You must believe that when one repents the Lord wipes the sin completely as if it never occurred. So be of good cheer, have faith, and hope in the Lord our God.