Telling someone who expresses suicidal feelings to "get a grip", and using the J-word ("just") to tell them a supposedly easy way out of it, is cruelty. I'm sure that you don't mean to be cruel, so please don't do this.

If there were an easy way out, the commenter would have found it. What he or she needs is respect, empathy, and support for finding a not-so-easy way out of it. If you can't do that, please don't reply, regardless of how annoying you find the comments.