Even if your parents are nice its not okay to invalidate your emotions. The best I can recommend is that you find ways to let it out in private, even if its just a 3 minute cry break in the restroom with the door closed. If you do it in private you might not be able to shate the feeling of doing it for attention, but remember, people who are actually doing it for attention know theyre doing it for attention, and theyre not wondering or worrying if that is what theyre doing. If you cry/let out your emotions in a private setting, the feeling might still poke at you, but I garentee if you let out your emotions like that then that is solid proof that youre not doing it for attention.