Please Help! How do you masturbate?

I am in my early 20s and I've never been able to get off on my own. I truly find it frustrating that I've never been able to masturbate. I want to so bad because it seems so freeing and empowering to be in control of your pleasure. I have toys, but when I use them on myself it feels like nothing and I've tried my hands, but again nothing. It's like I'm not turned on and like I can't get out of my own head. I want to focus on the sensation, but I can't. I'm truly jealous of people who can pleasure themselves. Has anyone else had trouble masturbating and then found a way to do it? Does anyone have any tips?

Update: Let's just say that the showerhead was a success!!