Do both.

Give up on your current starter and bin it. Start a new one. I think most start with a 50/50 mix .. but make it with ordinary hard flour or perhaps rye. Keep in mind you'll need more water if you use other than white as they all absorb more water. Have a look at some youtube stuff for consistency. If you look at the first post i think that is about right.

At the same time make poolish in your normal mixing bowl. Quick standard white bread flour and quick mix with a fork and put a shower cap over it. Do the poolish tonight for a loaf tommorow.