Yes we are geeks, and yes you can do this yourself.
Here's a page from Leafly on how to do this from scratch.
One quick n dirty recipe for making CBD topical from the Green Mountain CBD edible salve ( 600 mg / 30 ml, $30 so far):
Mix and if necessary heat GENTLY to get it to mix.
This makes a 2 mg CBD / ml gel to try as a topical. Just information.