I can do it by myself but no one can do it for me.

Since as long a I can remember I've masturbated in the privacy of my own company. Even as a little girl I would explore my own body. There were only three times since my childhood till my teenage years until I went off into college did I ever get caught by my parents. And none of those times did I ever get sat down to explain what I was doing and the last two time when I was older did I get told I shouldn't. I knew, though, that it felt so good that I couldn't stop. This was after a period of a month that I stopped and I got so worked up that I couldn't focus on anything and my attitude began to get very grouchy. Since then I haven't stopped. That is until my ex and I got together. We were together for 7 months and he was my first true sexual partner. But nothing came from it except disappointment and fights till eventually we broke it off. Then I got together with the girl I'm with now and love dearly for the past 5 years. Still even with a very dedicated partner I still can't achieve the big o unless I am by myself and usually with the help of porn. We've tried everything we can think of. Fingers, tong, toys, talking about it, talking about different ways and techniques, opening out relationship and having sex with other people (always agreed upon before any actions were taken place of course), but nothing has even come of it. This leaves her very upset and me very frustrated about the whole thing. I've only had a very small handful of orgasms while I played with myself but they weren't that powerful and left me very frustrated even though she was ecstatic that I orgasmed in front of her. I need advice as to what I should do. I really want to have a healthy sexual relationship, but how?