I'm not sure IF they'd really fit or be that comfortable but there are companies like NYDJ who make jeans that have a degree of elastication on them so they sorta.. suck in the belly area and squish in the waist like support underwear.
But i'm not totally sure how well they'd work or how comfy they'd be for a transwoman but worth a look maybe? Has someone tried them?
Long tops would definitely help, actually I suggest looking up "how to dress for a ruler shape" because some women actually ARE straight up and down with no real waist definition. It's a challenging shape to dress for (lots of colour blocking and layers) but not impossible to look feminine and lovely, lots of floaty layers and frilly bits which depending on quite how girly you wanna go, might actually really appeal anyway.
If you have a little squishyness you'd like to squash in, body form/shaping underwear can help, a lot of cis women wear them to suck in that extra belly bulge lol. They don't really do anything perminant, you'll still have the paunch once you take them off, but they will suck it in for getting into something you want to feel a little more smooth and svelt for (think like, sliding yourself into a lovely frock)
I get you on trousers though, women's trousers so often have a really short groin/crotch and sit on the hips rather than the waist or come up to your blooming armpits. (I hate this, I haven't been able to find women's trousers I could fit into in years! )
An awful lot of AFAB women can't fit high street trousers because they're stupidly tailored as well.
I reccomend shopping around, a lot (if you haven't already, i'm sure you have) Find a store who's tailoring works for you. Every single store has different sizings and dimensions (why women's clothing? WHY?) so one store's styles might be totally wrong while another's near identical looking garment might fit just right. Be prepared to really have to work for it though.
The frustration of finding clothing that fits and looks nice, oh... it's almost like a woman's right of passage.
I mean genuinely, pre my gender revelation I had spent YEARS going through the nonsense of trying to find clothing that fit my body shape without looking frumpy and awful. I actively put off buying new clothes because I found the process so depressing (because nothing fit right rather than because of clothing dysphoria, i'm actually still AOK with wearing skirts, they're pretty)
Skirts are btw, AMAZING. Not only are they often really comfy but the more floaty or tiered styles give an illusion of hip that can look really quite gorgeous.
Also, they come in so many fabrics and beautiful patterns and in the winter a long skirt will keep you SUPER warm with some stockings underneath (the fabric traps your body heat underneath the skirt so you have your own little warm tent hahaha)
I highly recommend skirts, they hide many.. many.. many buldges and undesired squishy regions like beer bellys (I have a pretty good beer belly) and love handles.
Have fun trying on everything! Seriously, if you're still trying to find your style don't be afraid to take like 20 things into the changing room and just try them all on in the privacy of the cubicle. Even if you decide none of them are for you, it doesn't matter!
(why do you think Cis women spend all day shopping? hahaha, they try on half the store!)
I know a lot of us shop in this rather self concious sort of way, seeing something we kinda like but know is really "a bit unconventional or odd". A sort of guilty pleasure and you dismiss it. you go "no, I won't try that on, it won't suit me, I won't wear it" and you miss out on finding potentially something you never imagined would look so good. Also it's fun and healthy to indulge that guilty clothing pleasure! Least I believe it is heh.
Anyway I hope some of this is helpful. Maybe?
I'm AFAB but that does mean i've lived 30 odd years dealing with the awkward sizings and shapes of womens clothes coupled with a body that really isn't entirely conventionally feminine (I have high testosterone naturally so my fat distribution is far more typically masculine resulting in the beer belly or, depressingly if you're female, the "where is the baby due?" gut. EUGH)
Do you have any female friends you can go shopping with? A second oppinion on garments is often quite helpful to some people (I prefer to be solitary and very efficient and directed but then, that's my funny ol' boy brain isn't it?)
I know my mother often drags me to clothes shops just so she can get a second opinion on a dress or a skirt or a blouse or something.
Good luck finding your personal style! I'm sure you're gonna have fun once you figure it out.
Shopping for garments you actually WANT to wear is a pretty joyful experience.
