I have been known in my local area as a loud singer of shanties and chorus songs. Over the last few years, though, I choose quieter and more reflective songs. I have chosen to sing those songs which have a chorus or refrain, although they might not be my first choice of song, they are those that I can still use to good effect by "barking" the first chorus, but I can still do that. I can still take an audience from rowdy to tearful. Just don't ask me how, I don't know how.
I don't quite know what goes on with you, and I won't try to guess.
Singing, for me comes from the heart. However I remain aware of what the particular, rather than the local partisan audience wants. There are times for "The Galway Shawl"; there are times for "Molly Malone". I am sure that sometime there will be a time for me for "Carrickfergus", I hope and believe in that, but it hasn't happened yet, in nearly thirty years.
A quiet voice is not a disadvantage. You probably have a sensitivity for song by virtue of your reticence. I really hope that you have friends about you who will support your singing talent beyond the classic mc statement "quiet for a lady singer".
Please MC if you wish.