Hi Josie,
it's not that pastels aren't your medium, it's the pastels. You bought cheap wax crayons claiming to be pastels, and that's why you're frustrated. So it's not you! I went through the same.
In my experience, there are only three brands of pastels worth buying:
Mungyo (from South Corea)
Caran d'Ache (from Switzerland)
Sennelier (from France)
The Senneliers are the creamiest and behave most like oil paint. Like oil paint, they have varying degrees of transparency, depending on pigment. So if it's opacity you're after, you're better off with the other two. They're also more matte. Unfortunately, neither brand is inexpensive, but they're absolutely worth it.
Caution: Caran d'Ache has two lines of pastels, Neocolor I and Neocolor II. The oil pastels I'm speaking of are Neocolor I. The Neocolor II are watersoluble wax crayons and just as hard as yours! The product naming is really unfortunate.
Lastly, there is a way to improve cheap oil pastels if you don't have the budget for the ones I mentioned here. I wrote a DYI article about it, here:
@wulff-media/sht-to-shinola-diy-oil-pastels-tutorial
Cheers - Folker
P.S. For best pigment coverage, i.e. no white showing through, use Pastelmat paper by Clairefontaine. Another expensive art supply but also worth it.
RE: Pastels that didn't work out