Some very tricky comment) do not take everything personally) There are quite a few reasons why you cannot get an orgasm. As already said, not everyone gets a vaginal orgasm. Size is also not always important, some of the men have a poor sense of rhythm (or simply cannot recognize yours). Maybe his penis is under some kind of inappropriate tilt by itself. In any case, this is not a problem. Don't think, "oh, I didn't feel anything, it's all about me." Experiment, try different positions, angle, penetration, and more. Do exercises for the muscles of the vagina) and do not fancy yourself too much)
I read your comment and decided not to delve into the jungle of all your relationships. But I'll try to answer the question. It's okay with your vagina. How much has already been written and written that only about 30% of women get a vaginal orgasm, the rest of us have to be content with a clitoral orgasm. So be glad that you have an orgasm with at least one, then it is doing something right. Very often, two partners cannot find a rhythm in sex for a long time, and even if both of them are "nothing" in sex, then it is not at all necessary that they will succeed at once.
Further, if you are already completely worried about vaginal orgasms, then do regular Kegel exercises, you may just have weakened muscles, and Kegel exercises are very helpful, you just need to do it regularly, several times a day. Hope it helped.