Almost any commercial potting mix will do. There is no trick to it. But you can screw-up a commercial potting mix by adding shit just to add shit, too.

Even MG soils (which I first learned to grow cannabis in) are fine if you adjust your nutrient schedules to reflect those additional nutes.

IMHO, compost isn't potting mix. It's an outdoor soil ammendment. Chicken compost, horse and cow compost, mushroom compost...none are any good on their own, but under the right conditions, are a good addition (component) to the soil.

Regardless of the potting mix you chose, I'm sure we can talk ya down from taking the hydro plunge. (where all you'd have to change...is everything)
I'd go get some potting mix, and try again, with a little help from us along the way. :jointsmile: