If you want to stick with oil investigate the paint brands; I have seen oil paint that had on it written “Matt” but this was a while ago.
Other then that, Try Acrylic!
I have used acrylic, it gets a matt finish. I use glycerin if I want any sort of glossy finish on it.
The acrylic you can layer like oil. If you get the higher quality acrylic’s they work pretty much like the oil paints in this way.
Higher end acrylic will NOT yellow (even the cheaper stuff wont yellow)
(Though yellowing could also could be a sign that there is other acidic contaminates around)
Acrylic also will dry much much faster then oil. You have to be careful when your first working with it because of this. You can use glycerin to slow down the drying and make it more oil like in it’s workability.
The stigma against Acrylic is not deserved because there is a huge difference in the art acrylic and the craft paint acrylic, and that’s what people are trying to stick there noses up at. If you got to the art section or an art store you will see the good acrylic there.
It’s, unfortunately, not really cheaper the oil.
So try it, you might be very happy with what you see!