The Dutch painter Vincent Van Gogh was many things (not just the inspiration for Don McLean's 1971 hit song), but we remember him most for his numerous self portraits and his lovely starscapes. Van Gogh was not famous during his lifetime, but his posthumous fame shows us a man who not only was an incredible artist, but also a man of great wisdom. Much of the information we have of him is from correspondence between him and his brother.
One thing I find particularly inspiring is this thought from him: "The fishermen know that the sea is dangerous and the storm terrible, but they have never found these dangers sufficient reason for remaining ashore."
He also said "If you hear a voice within you say 'you cannot paint,' then by all means paint, and that voice will be silenced."
Don't let things hold you back even those voices of self-doubt from within. Just do it!