There are a lot of posts on this site about girls who have not yet reached orgasm and are trying to do so -- my question is a little different because I have already reached orgasm.

I, however, have only reached orgasm one way, and this worries me. The only way that I can have an orgasm is if I lie on my stomach and use a pillow or my hand to apply pressure inbetween my legs and rock up and down - hump it, if you will. =)
Now, the problem is that I can't reach orgasm any other way -- and this wouldn't be a problem for me if I didn't have a boyfriend who thought he was bringing me to climax all the time. I'd like for him to be able to get me there, but I know a lot of the work has to come from myself. (We haven't had sex, he just fingers me and sometimes eats me out)

So, I began trying to fix the problem by masturbating in a different way. I read For Women Only - Help! Why Can't He Make Me Orgasm? and other things that talk about masturbation technique, and I've tried it for long periods of time without giving up, but nothing brings me to climax. I can't even do the same thing that I usually do while lying on my back. And the closest I've gotten to climax with my boyfriend is spitting out a hot fluid, it feels really good, but it's not an orgasm.
This makes me feel terrible because not only is he the only one reaching climax every time we engage in sexual activity, but he thinks that I am too. I'm not expecting to have an orgasm every single time like he does, but I never have. And I realize my first mistake was telling him that I ever have with him, because now it's so late that if I told him I never have, he would question his trust in me. Not to mention, only being able to have an orgasm one way makes me feel like something's wrong with me.

So my question is -- is this just because I have trained myself to have an orgasm only one way? Does this mean I can never have an orgasm from sex or him fingering me and massaging my clitoris?