I remember we had this conversation before in another thread.
Drawing with 1px brush is crazy
. I urge you to stop this bad habit asap.
That is why you have the pressure sensitivity.
Also remember to downsize the map at the end. It will look better.
Usually people do digital art 3x bigger than the final outcome.
For example if your intended map is 2000 x 2000px, then make it 6000 x 6000px.
Having bigger map than intended gives you more space for details which will not force you to use such a thin brush and you ca also go a bit messy with the details, because in the end when you resize it down, the messy details will look better, so to speak
.
I usually make canvas 1.5x to 2x bigger of what I really want. Later I will downsize the map to 75% or 50%.
Hope that helps.