I own a vibrating wand that I use on myself for clitoral stimulation and it always feels great, but I don't think its ever enough. I feel like I'm masturbating wrong because I can never reach a point of relief. I'm hoping at least one person can help me!!

I know what makes me feel good, because my legs start shaking and my back curls up and I get really tense. But I continue like that and nothing happens other than me getting so tense that it eventually becomes uncomfortable or I can't move so the stimulation stops. I do "cum" but I've always had to kind of push it out when I'm masturbating and all of my girl friends say that it should happen on its own without feeling pressure or tension. And when I finally stop masturbating, my vagina is left throbbing and I don't ever feel satisfied.

What am I doing wrong? I've read every article I can and they all just say to stay relaxed and keep trying and get to know myself, but it's been a year and I still cant figure it out. Someone please help me!