Raping a kiss is usally a bad idea, and shows that the person doing the raping has zero respect for you and your wished, and that your needs will happily be sacrificed at their whim.
tip: if it involves intimacy rape of any kind, whether gential+genitals or even just groping someone in spite of that they do NOT want you to, and you're very well aware of it... I don't think I need to end that sentence, now do I.
Therapy sounds like a good idea. Or just ask her to kiss you on the lips, both of you with closed mouths. Get her to do it often enough (by positive reinforcement, not punishing her if she doesn't "obey") so that she'll get used to it, and enjoy it quite a lot, and do it freely. Then work your way up to get her to kiss your closed lips, her using a more and more open mouth, and then gradually start kissing your more and more open mouth. Expect this process to take half a year from closed kiss to open mouth kisses.
Also, you should check if you have halitosis or anything.
She may not have a bad breath, but you might without realizing it. Do not feel embaressed or bad about it, as it was not your fault, just remedy it if that's the case.
It may also be an issue of your lips. Take care of them, ensure that they're soft and supple by using good lipbalm, and also brush your lips with your toothbrush when you brush your teeth, to clear away dead skin, and apply lip balm on them after that.