I think someone wrote your name and number on the proverbial spirit bathroom wall.
Ok, maybe not such a good joke. Perhaps this is YOUR calling. You will be led to those who you need to help, rather than you calling spirit to you because of the beckon will of those on this plane. I don't know if that makes sense. In other words, there are things people want, and there are things people need. Perhaps you are moving from the things people want to the things people need. If you feel drained, make it be known - and take your time. Spirit will be there tomorrow or the next day if it is something that is truly needed. Some have the view that protecting and shielding blocks all negative feelings and emotions, but to me feeling the grief of the spirit or of the person receiving the message is not always a bad thing. There is understanding, and then there is truly understanding? That's my take.
Anyhow, I wish you well.