On Monday, hours before Kaitlyn Bristowe's episode of "The Bachelor: The Greatest Seasons — Ever!" aired, Nick uploaded a shirtless mirror selfie and captioned it, "Because I get dumped AGAIN on National TV tonight."

His comments section immediately filled with a mix of positive remarks, as well as others arguing he looks too skinny. One person wrote, "90lbs soaking wet...I am sure there is a steak out there with your name on it."

Another added, "So thin you need a burger !"

Fed up with the feedback, the Season 21 Bachelor posted another shirtless selfie and wrote a long caption about how "the comments made me feel self-conscious."

He began, "Dear internet.  I never thought you would make me self conscious about my body. Yet I woke up to hundreds of comments on my last post about my weight, eating habits, and mental health all from posting a post workout pic where I looked particularly lean. I have never lacked confidence about my body (I know this isn’t news to most of you) but if the internet can get to me it can get to anyone."

His caption continued, "So Im just saying, be-careful with your words before you give your feedback on peoples physical, emotional, or mental health. I don’t want to even admit that the comments made me feel self-conscious, but I assume many of you would think I can’t be bothered. So I’m here to say it did.  I hope thats ok."

Nick argued in his note that he doesn't want to have to justify his health and eating habits, but the criticism has forced him to do otherwise. "I don’t feel like I should have to say that the past few months I have been running 4 miles a day and feel like I am in the best shape of my life. Or that I eat bacon and snickers ice cream bars everyday," he wrote. "If told you how much pasta I eat, I would just annoy you."

He warned others to "just be careful" when they decide whether or not they want to call someone else out for their looks or a "bad angle."

Nick concluded, "A pic doest [sic] tell people’s story. You could be stripping down months of work and process someone has made on their own self improvement. And god forbid you cause them to never want to post shirtless selfie again.  Me…I”ll be ok (Im still pretty sure I look fantastic naked)."

Cyberbullying has been a topic of conversation among Bachelor Nation cast members for years. Blake Horstmann opened up on "Bachelor Happy Hour" in September about his experiences getting "lots of death threats" after "Bachelor in Paradise." Julia Rae from "Listen to Your Heart" also dealt with "brutal" cyberbullying.

Rachel Lindsay spoke out about the problem on Peter Weber's "Women Tell All" episode and urged people not to spread hate online.