I find that those are the harder things to come to terms with in terms of being in the wrong body.. things that you know you can't ever change. I mean, with the way technology is evolving, i'm sure some day in the late future there will be surgeries or things to make your inner organs develop as female or replaced as female... but we are far away from that day (I would think, but one can think positively)
I personally find no dysphoria in not being able to get pregnant, have my period, breast feed, etc. however I am always constantly thinking about how I missed out on my female childhood... how i tried desperately to feel or engage in it... but it was denied to me.. I had my girl friends with their barbie dolls and my spice girls fad and my girl friends at a young age who just treated me like another girl friend. But i was denied the cute outfits, the swimsuits, the training bra stage, the boys (or girls), the whole female childhood experience... its something i wish I would have had because its something that I think would have greatly changed the outcome of my life... maybe i would'nt have been the only 13 year old boy in my middle school who talked about death philosophy and how life is tragedy incarnate... maybe I would've had a sunnier disposition or more friends, or a better social life. I want to have a daughter so bad so I can re-live my childhood vicariously through her, and do whatever it is she wants to do... but this is of course just a hope of mine, i would never force my daughter to do or be anything because of what I missed out on.. but i guess i see that hope as a way of experiencing with her everything that I was denied, if she so wishes to be the average little girl. Of course, i would support my kids whether they are boy, girl, trans, intersex, variant, animal, alien, mermaid, Minotaur, dragon xDetc lol. But a girl can dream T-T lol
Anyway, don't want to get your hopes too high but... if i recall correctly, it IS possible for a cismale to lactate and breastfeed their child... let alone a transfemale, you're getting all the necessary hormones. Look it up

there are ways... whether or not its safe to do within transition or pre/post transition is a different story, but if you do a search, it is possible :3 hope that helps to some degree xD
try to find appreciation in being called mommy, and always remember that your body doesn't change that you are his mommy

I'll have to settle for Mom or Mama because my wife already claimed the "mommy" title >_< Try to keep in mind the cis-women who arent able to lactate or breastfeed, or the women who are unable to have children :3 and hopefully it will give you some sort of solace that despite what you were assigned at birth, it could still have happened if you were cis. In a way, that's one of the things that allows me to let go of those things ~ i just consider myself a sterile woman

The goal of being seen as a woman isn't unreachable

Something I've kinda learned to tell myself (even though i'm a very VERY impatient woman), is the following:
"Even if I don't pass in a year... i will definitely pass in 10" lol... because what i've noticed from transwomen who transition who feel like they aren't passable or might never be... at some point, the hormones do SO MUCH WORK on your body that there is NO WAY you CANT pass

after 10-15 years your body will have been reworked by the hormones so much that passability becomes a thing of the past and the rest becomes a vanity status (body, boobs, butt, being hot, etc.) granted; its not the most comforting of notions because... hell.. 15 years is a long freakin' time >_< but better late than never xD
anyway; i hope my unnecessarily long response and possibly pointless tangents I went on somehow helped <3