I think your real problem is self-confidence. The sun gives your identity or sense of self. Your sun is conjunct Uranus and Neptune, who are constantly upending your sense of who you are. You also have a big T-square, creating inner stress that makes you doubt (Saturn) your artistic ability (Venus) and roils up your emotional state (Mars-moon.)
As to your talent: Venus is the generic ruler of the fine arts. It is helped out by a conjunction with a domiciled Jupiter (in the sign it rules.) She’s got a powerful best friend in Jupiter.
Mercury and the third house rule communication. Your Mercury conjuncts you MC (vocation) from the 9th house, which rules literature. Mercury rules your rising sign of Gemini. Your moon (emotional nature) and Mars (assertiveness) are in the sign of Virgo, which is ruled by Mercury. Your third house is ruled by the moon, which gets us back into the Virgo-Mercury loop.
You’ve got talent. Truth be told, you also have ambition (quintiles.)
But– with self-esteem as a hold-up for you, make sure you have a strategy for dealing with rejection letters and critical feedback. When this happens, take a moment to scrape yourself off the floor, but then get back to work. Be ready to make necessary revisions, and then to try again. If your work shows promise but needs work, be ready to make the improvements. Then re-submit your writing.
This takes self-discipline. Given your powerful Saturn, you can develop it.
Good luck to you!