Hesitant to share the only thing that matters... my justification remains

I want to be a person who is always on the lookout for opportunities to share the gospel. My life is worth nothing if it is not used to share the gospel. My justification is not changed. Not even for a split second, and God will receive glory from me regardless. Nonetheless, I am called to always have the gospel on my lips and speak it at all times. I had the opportunity today to share it with a stranger, yet I didn't. I don't want that to happen ever again. Never, ever again. God has those who belong to him. And my duty is to preach the gospel. He will use my stumbling words and nervous tone to draw to himself those who have belonged to him since the foundation of the world. Thus I must speak it.

Yet, in this I rest. That I have failed yet again. That I was disobedient, and once again showed that I am deserving of hell. Yet Jesus has paid for everything. There is no more wrath for me to drink. I get to drink the cup of God's salvation because Jesus drank the cup of wrath and earned for me the cup of salvation. My relationship with the Father is not hindered. And out of love, I am free to obey him.

I am frustrated with myself. But that produces growth. I have to remind myself of the truth of my justification. I can't allow my emotions to control how I view the truth. God says I am justified- I am justified no matter how I feel. I have to ask my Father to give me boldness to share the gospel. Paul in one of his letters asked the church to pray that he would have boldness as he ought to to share the gospel of Jesus Christ. That is a prayer request of mine, also.