I think you have been really brave reaching out with something that is sharing a real vulnerable part of you. Its a 'deepest fear' thing that actually is more problematic if you hold it in than express it.
What you have found is that you are not alone in this feeling. Its a feeling though that unmasks deep dissatisfaction.
I encourage you to really spend some time thinking about what does make your heart sing.
And even if its baby steps , make steps towards doing some of that.
To find something that makes your heart sing, I would ask you to try to take your mind off this for a few minutes and look at what you used to choose to do when you were a child. Was it read, dance, theatre, craft, fish, ice skake, ballet?
Then make a plan to do this thing at least once a week/fortnight/month.
Awareness needs to lead on to action as without action it is easy to sink into further despair.
You have been brave to reach out and so you can make changes and put yourself higher up the list in your life.