Hello; to help overcome your fear and familiarize your mangyna as you say, me I prefer ass, since functionally it is an exit, yet for sexual pleasuring that area requires letting your ass get used to at first a small shape, I started with pencils when I was 15, dildo's were not readily available especially to a punk kid like I was, LOL more to the point. I experimented with some things, but nothing compares to the real thing, when I was older in the military I had an experience with another man he was smaller than I was, he fucked me for half an hour at least, wow! ! ! WOW. He was laying on top of me with my knees on his shoulders, my ass wide open to his hard 6 inch cock. He was gentle as I told him he was my first, and after he was in he took his slow time entering my depths, only an inch at a time. after about five minuets he was balls deep in me, and I was whispering for him to fuck me , fuck me good. We were doing this in the barracks, with other GI's across the hall
gotta be quiet ya know.
After this it would be 6 more years before I would try anything again, but more to the point strap on didlo's are easily available these days, you could have such sex with your wife wearing the cock, fucking your ass with a small cock moving eventually to a size you are comfortable with. And with this you also avoid possible disease issues, with it just between the two of you.