When it comes to masturbation, giving yourself permission to explore and experiment is big part of it feeling good. Have you tried a lot of different ways of masturbating, or have you mainly focused on clitoral stimulation? And when you're masturbating, are you mentally aroused as well as physically aroused?
With porn, while some people enjoy it, others find that it doesn't do much for them (or that they prefer a very specific kind). It can actually be a more helpful starting place to connect with your own fantasies, and try incorporating those into masturbation, whether through porn or another means: How to Approach Sexual Fantasy and Desire on Your Own Terms