ArtVandelay, thanks for the great topic!
I would encourage you to investigate local Toastmaster's (TM) Clubs in your area. They are public speaking groups which anyone can join to develop the qualities that you may aspire to develop. People can get over fears and complexes as well. The whole philosophy behind Toastmaster's is "praise, improvement, praise" (PIP). This means peers will encourage you to develop yourself in positive ways and draw your attention to behaviors you can work on. You can typically be a guest at a club for a handful of meetings with no financial obligation or requirement speak aloud if you don't wish to. Some members even just attend meetings from long epriods just listening and watching others. The cost to join as a member has benefits you can find out about based on your interest.
Guests and members are given opportunities to learn how to be less self-conscious and to build their confidence which can spread into otehr areas of life outside TM.