Just to add my $.02, bread consistency is pretty basic. If it's too stiff - add water (just a tsp at a time). If it's too "pancake batter-like" add a little more flour. Here's my suggestions: #1 add a bit more flour until you are happy with the consistency; #2 add approx 1 tsp of "instant" yeast.
Instant yeast is different than "rapid" or "fast rise" yeast. It is often labeled as "bread machine" yeast. It usually comes in a small jar - not packets. Instant yeast does not require any pre-activating. Just add it directly to the flour, or in your case, the dough (then knead it in). I know you are using sourdough starter and it shouldn't require any other yeast, but often the starter is not active enough, so a bit more yeast will help your situation without affecting the flavor.