Did I mess up my starter? (1st timer)

- 12/1 with 100g of Artisanal Bread Flour and 100g of water to start.

- 12/3 it has risen to doubled in size, so I discarded all but 100g, then added 50g/50g artisanal bread flour and AP Flour and 100g of water.

- 12/4 it has risen to doubled in size, so I discarded all but 100g, then added 100g AP Flour and 100g of water.

- 12/5 it didn't really do much

- 12/6 (today morning), woke up to almost liquidy texture.

Did I just kill my starter?