it appears that I can buy the form used for estradiol pills

You can also buy the pills themselves. ~~hrtcafe.net~~ (hrt.coffee is the one I was thinking of, hrtcafe.net might also be ok but idk) is the resource that gets recommended for sourcing suppliers, and if you live in canada or the states at least then it’s legal to buy estrogen online (although it might still get seized by customs). As far as making your own pills, I remember that being surprisingly difficult, but you can make estrogen gel, as others have mentioned

Going back to pills, taking them sublingually (dissolving them under your tongue) is very effective and you can actually achieve pretty high levels this way, although it does get processed quickly so you get a big spike of estrogen that goes down quickly, so if you’re taking multiple pills per day it’s better to spread them out over the day instead of taking them all at once. On the other hand, taking the pills orally (just swallowing them) has a smoother curve, but is less effective and has a higher risk of blood clots.

Just make sure you get estradiol/estradiol hemihydrate or estradiol valerate (which is a little less effective than estradiol as a pill but still works fine) and avoid ethinylestradiol, which is a synthetic estrogen and has a higher risk of blood clots

Edit: diyhrt.wiki is a good resource for learning about this

Edit 2: unless you’re doing monotherapy,you also need a T blocker. If you’re doing diy anyway, I would recommend cyproterone acetate over spironolactone; it’s more effective and has less side effects. Just don’t take the whole 50mg pill, a quarter of that, 12.5mg or ~10mg, is enough and you might be able to go even lower. That said, estradiol monotherapy is apparently possible with sublingual, even though most people use injections for monotherapy, so that’s also an option