It also might be, that you need a right person to experience the orgasm with. I mean, a long route, getting attracted, dating and so on...and then sex...and if you are aroused enough, it might happen, with a right person. Perhaps not the first time, perhaps not the second, but it can.
But just trying to achieve orgasm for the purpose of getting it, will make it impossible.
I noticed pre-op that I lost the ability feel pretty much anything downstairs after some months, didn´t feel a thing.
But there has been few guys who I really liked and I could experience my first ever anal orgasm....and later something else, that I cannot describe, it wasn´t anal sex, but just licking me on the area where the vagina now is, made me feel something that I hadn´t experience ever before.
You need to give it time and relax. I know, you´ve heard those words before