Adding guilt to anxiety
This is pretty much the worst response to "I'm feeling anxious." besides "You are a terrible human who doesn't deserve the air you breathe." because it pretty much means the same thing to an anxiety sufferer. We already feel irrational and stupid that we're anxious, so saying it could be worse invalidates those feelings and makes us feel even more awful for having them in the first place. Of course it could be worse, it could always be worse. But how about asking "Is there anything I can do to help?" instead. Thank you!