I struggle with the fear that, no matter what I do, I have passed the point of no return.
Do believe, do have total, strong faith in the fact, that it is never too late! If you sang well in the past, certainly you have the potential to sing well again: a little change of style, a little change in tempo, a small adjustment, adaptation in pitch, and some support from supporters like the 'sruti box' or 'tambura' and any accompanying instruments that you may have, and, maybe, prudent selection of items you sing, — you will certainly sing well again, i am sure! please sing again, keep singing, do not give up!