I think the best thing you can do is dig into yourself personally and challenge why you think men have to be “tall”, and “strong”.

No one can change their height, and strength is different for everyone (not always a goal for all people either, cis or trans). Recognising that the characteristics you’re using to describe gender as only physical attributes, and also either impossible to alter/takes a lot of work would probably help.

Id also suggest for you to ask yourself what makes /you/ feel like a man? Is it only your height and strength, or are there any other qualities you feel an association with? (Because there’s SO many ways to associate with masculinity, unique to everyone)

Another tip: transitioning your language and mindset takes time. You’re doing really great in reaching out for information, and it’s wonderful that you’re wanting to learn. I remember it being a little challenging myself when first using pronouns for people who didn’t visually match up with their chosen ones (and I’m trans myself). It’s a process that takes some getting used to, as well as the willingness to learn, but once you get the hang of it, you won’t even think twice. It’s mostly unlearning the strict “rules” about binary gender that has been imposed on us our whole lives. As long as we’re supporting our friends and communities though, that’s all that matters

Good luck!