Any ideas why my thyme keeps dying?

The plant just goes dry

The stalks go black and the leaves dry up and fall off

Soil too rich?

I’m afraid it’s a fact of life that thyme goes dry.

Maybe overwatering causing root rot? Is the pot well drained?

You must remember this
A kiss is just a kiss, a sigh is just a sigh.
The fundamental things apply
As thyme goes dry.

Keep cutting it down so it stays small and juicy

Needs sharp drainage and neutral to alkaline soil. Peat based company tends to be slightly acidic. Something loam based with 1/5 coarse grit by volume would be a good start. Don’t over water either, let it almost dry out between drenchings.

If it is in the ground then putting some gravel in the bottom of the hole to improve drainage would be a good plan as would some lime if your soul is acidic.