@brainiac
It's interesting to see how differently we deal with gaining ownership of our bodies.
As for my front hole, I imagine it as being my penis but... had to look up the word in English and the best translation was "invaginated"

but now I've also found "inverted". I once told this mind trick to a transwoman and she couldn't help burst out laughing.
Maybe the poor guy just got so frightened one day that he has just been hiding inside since that day.
(Sometimes, my front hole just becomes my back hole in my imagination, just like for you.)
The inverted penis trick is illogical as I also have a dicklit, but that's just my penis no. 2 then. A motion like jerking off for that little guy does not work, sadly, but maybe I'm just too clumsy. My outer labia are an empty scrotum for me, and my inner labia are something really weird which I don't know why they're dangling there.
All this remapping is not stable though, so I found techniques which help me during sex. One of them is orgasm control/delay, if I do this long enough I completely or mostly forget what body parts I have at all or don't care any more. Another technique is fleeing into an erotic world with my mind where things happen which have nothing to do with my genitals.
Plus, I've been looking at quite a lot of bodymod pictures some time ago, i. e. pictures of heavily modified genitalia. This has helped me see the usual 2 biological outfits as only 2 of many possibilities of what genitals can look like and somewhat break up the genital sex binary in my mind, so my dysphoria has decreased a lot for this part of the body. Any genitalia are okay for me to have now as long as they are not clearly female, and with the dicklit I already have a great body mod, and I consider adding more mods there in the future just to make my parts look even more "different from female".
That was weird, being forced to go to a therapist for a year and being forced to open myself to him to get testo has been very bad for my soul. Going to a piercing/body modification studio just once and go through their books has been like a great inner healing experience for me, and I made a huge progress in just a week. (I did not get anything extreme done there but got lots of information from the piercers/body mod guys plus a couple of fancy piercings). I also love the idea that when it's body mods, you needn't go through therapy and be medicalised etc. to change your body the way you want it to look.