wow, usually facial hair and a deep voice is more than enough for the "cis gaze" to pass someone as male.. i'm really surprised to hear that! i agree working on mannerisms will help a lot, maybe have a look at the way you walk, sit, move your hands as well... little things like that can sometimes be a give-away. the video idea is a great one.
you could also try different hairstyles, sometimes hair that's a little longer can frame the face or make it longer so it's easier to pass. although traditionally masculine, short hair doesnt always equal male-passing
you have a rounder face with wide eyes, so maybe something that is short on the sides and longer on the top like a crew cut could help make your face more rectangular.
if its possible for you, growing more of a beard might help too, and will give an illusion of your chin and jaw being longer than they are. and it's nearly impossible to convince cis people that obvious beards can grow on anything but men. (which of course makes things really difficult for women, but validating for men).
all the best to you though, i hope the misgendering stops soon.
[edit]: a couple of extra tips i forgot to mention...
* when people misgender you i would avoid getting defensive or saying things like "actually i'm...". when cis people get misgendered it rarely happens so they treat it as something ridiculous, because they've never had to prove themselves before. laughing it off and saying like "um, ok then." puts the blame onto the person who's misgendered you, and makes it look like they've made a mistake that's clearly obvious, rather than you trying to prove yourself. that extra confidence can go a long way in shifting peoples' perceptions of you!
* as far as speech therapy goes... i've never personally been, but i spent years trying to "naturally" transition eg doing vocal exercises to deepen the voice and things like that because i never thought medical transition would be an option for me. you can find a whole bunch of videos on youtube on different ways to help your voice and vocal patterns sound more masculine, and you've already got the effects of T for your pitch so it hopefully shouldnt require as much work
learning to speak from the chest to bring out as much resonance as you can goes a long way. also be mindful of consonant sounds such as S's, T's, and K's... extra enunciation on those can sound really feminine, regardless of how low the vocal pitch is.
absolutely don't exclude speech therapy as an option if you have the opportunity though!! i'm sure it will do absolute wonders and the effects i've seen from others who have been are mind-blowing. but these are just some tips to save your wallet
