Hi. There are persons that will thrive under criticism or stress, succumb to it or let it affect them a lot, or somewhere in-between, having that desire and some belief and self-motivation, but still being afraid.
I was a mix of all three at various points of time, depending on the task or goal, but one day I said to myself, "I will at least try, but not put pressure on myself to be the best, but to just focus on my efforts and enjoying it. Whatever happened after much practice, patience and persistence, the worst case scenario I felt was at least I would learn, improve some, and face my fears.
I figured, "How can someone who didn't talk more than a word or two to others almost all his life, who looked and acted too shy, and avoided almost all, and with no friends, and who felt afraid of singing and public speaking, actually try such much less succeed, and if it was others who thought I would fail, or myself then that had doubts too?"
Well, if you have a passion for something, anything is possible, if you have the right attitude, go step by step, put forth the effort, and have realistic expectations. I told my vocal music teacher last year during our first meeting, "I have no high expectations to be successful. If it happens great. If it does not, then fine. But, I will give 100% and I want to learn every detail of singing, and go at my pace, and to sing in my style, that I feel comfortable with."
I also said, "I will mess up many times, or seem so awkward, shy and nervous at times, but that is ok for me, and as it tests my strength to stay and work through that." I further then explained to her that "My goal is to learn to relax and have fun, with time, through the learning process. I look forward one day to look back at where I began, and how the final result would be," though learning occurs daily even for music professionals.
And I feel I have made great steps with my singing. Even the vocal instructor was really impressed with my progress, and saying how I learned and applied everything much quicker than the average student, despite my shyness.. Although I never sung ever before until last year, I had the foundation to sing from my ability to recognize pitches from a lifetime of listening carefully to music, and as I love anything that requires detail and analysis.