Oh yeah, I have had my fair share of tears! Most come from an intense rush of emotions and some from frustration. For me, they are pretty amazing, as I used to be someone who used to bury my feelings deep down. So to cry in front of WB just lets me know I am feeling and reacting to my emotions.
I know it used to worry WB a lot, but once we started to understand that good tears ( those brought on by a good, intense session) are good, he doesn't let them worry him so much. That is not to say he doesn't check to make sure I am ok, but that we don't always stop what we are doing because of a few tears.
I always feel a bit washed out afterwards, but also amazed at the emotions D/s can bring. Having WB stay online with me till I am feeling better again is also very important.
Hope this helps in your understanding of online tears, at least how they affect me.