Im to young for these manga?

ok, so i LOVE manga, but i accidentally stumble upon some pretty bad stuff. I think im to young for some, but i really like the story lines! like i just started Gantz and the plot for that is really awesome! yet there's a lot of nudity, sex, and gore. It does bother me, i usually skip ahead, but i want to keep reading :( I watched death note when i was like 12 and it freaked me out a little bit. ( still it was the best ever!) I've gotten into survival manga lately like limit and cage of eden, which are also very graphic. should i stop? is this healthy not to mind it much? im still under the age of 16 and see some stuff that im scared i shouldnt be seeing. any advice?