People only have the power to hurt you if you give it to them. If you want to help your little cousins, always be there for them and shower them with confidence and positivity. Your grandparents can only judge harshly on others because they themselves did not live up to their own expectations, and are incapable of accepting the responsibility for their own faults and failures and pointing out and degrading others is how they fill that hole in their hearts. I know it sucks, and it hurts hearing, but you've got to just brush that crap off. Are they really living in a position of life that is so much better than everyone who they are putting down? There is nothing you can do to get them to stop because they are set in their ways and have been relying on the crutch of hatred for so long they know nothing else, but you CAN take the power to hurt you away from them, as well as give your baby cousins the strength needed to be able to hear that kind of harshness and brush it off as nothing more than the mean old mutterings of crazy old fools.
My own family is full of this kind of hypocritically, "I'm sad and mean so everyone should be" kind of filth, and even though it hurts, I refuse to let it pass any further than my generation. I will not tolerate hatred being the only thing my family has to hand down the line, so I counter act it by ALWAYS being exceedingly polite, to the point where it's almost rude how damned nice I am to mean family members, and I let myself hurt at their words in private only for a little while before I take what they said, and reallky inspect why it hurt me and if I believe there is any truth to it, and if there is, I change myself to better myself and if there isn't, I ignore it becaue what do those fools know?
If you need to talk, feel free to e-mail me.
Also, self harm is a very temporary fix that in the long run, only causes more pain. I know what I'm talking about. I started at a young age, and my entire ride side, from my ankle to my arm pit is completely destroyed by scarring. At the time, brnging the pain to the surface, the rush of adrenaline that helped me stop crying and hurting, it was nice. But as soon as I woke up the next day, I would feel worse about myself for letting myself be so weak, and so on, an so forth. Now I've got the scars to remind me every day how much power I let everyone have over me, and to remind me to never let anyone have that much power over me again. They didn't deserve my pain then, and they don't deserve my scars now. I still feel the urge every so often to sel harm, but I've decided to take something negative and shameful and turn it into something I can be proud of. I will get a new tattoo, or piercing, that way I get to experience the pain and the adrenaline rush, but I will have something worth seeing, worth showing off for it, growing beauty from the pain.
Things get better if you have the mental direction and will power to make it happen.