Add the Dr Tim's now. And at the same time add the 1 ppm snack dose of ammonia. As 1 ppm ammonia is turned into 2.7 ppm nitrite, that isn't enough to push your nitrite level past stall point.
Once the cycle is finished, you will need to do a huge water change change to get nitrate down to the same as tap water. With fish in the tank, nitrate should be no more than 20, though some regions have almost 50 ppm in tap water which does make this a bit tricky. Can I suggest you test your tap water for nitrate so you know what level you'll be dealing with.