I want to get a tattoo even though I still live with my parents
How would your parents react if you got a tattoo?
I don't care what they are saying, I need to have this tattoo for myself
If you are old enough to get one, then it is fine, as long as you can afford it.
I hate these people for doing so much for me.
Hate is such as strong term for something that you may not really mean. You should be appreciative of what your parents are giving you as you may not have survived without them. I suggest that you reevaluate your relationship with them and see how you can show your appreciation towards them.