It would be helpful - in case you have not done yet - checking your Natal Chart. Your planets reveal some talents you did not know or develop before, tehy show the areas of live where you are stronger or weaker.
Feeling unworthy is a very embedded feeling in many people, mostly with xian background and education, as feeling unworthy "for god" is basic in the xian indoctrination. Their mass even says, the xian is unworthy and everything is his/her own fault.
So, if you have this buried feeling in your mind, confronting with this and working to get rid or reduce its influence, will open the doors to feel more confident in new activities. This may come from traumas in your early life. If this was the case, first or late you will need to confront this.
You are WORTH for something in your nature. Each of us is in his own way.
I experienced deep sense of being unworthy and I found, I gave up on things after a while, because "nah I'm no good, etc" while it was not always true.
What helped me, apart of meditations, several Munka session to reprogram the mind, was practicing a sport where "endurance" is required. This can be weight lifting (you cannot give up until you lift the weight or exhaustion), climbing (you need to reach the top), running for long distances (you need to complete your mileage for today), you name it. Something helping with improving will of "doing it". Sports is a very energy and self esteem booster.
It's never too late. I remember, HPs Maxine Dietrich often said she was quite old. So I understood, she gave birth to the JoS quite late in life.
TV, mainstream, show that only the youngest are "good at" in incessant tv shows promoting youngs as rulers of the world, and then you are "gone". But I see, most politicians for example are quite old, so they reached a high point late in life.