Zoloft

I just started recently started taking Zoloft. I think it’s working, but I don’t know if it’s a bad thing. Recently, I’ve just felt kinda numb. I feel like I should have a reaction to good and negative things but I just don’t feel anything, whereas a month ago I was soooo emotional about things. My best friend is currently in the hospital and it’s pretty bad, but when I found out I just felt absolutely nothing. And me and my boyfriend are currently having issues and there are times where I feel like crying but it just won’t happen. It’s just numbness. Could this possibly be the Zoloft? And is this lack of feeling a bad thing?