trouble with threads

..a Pierce relation with the Helix is a good thing.

Change the 2 lines at the vertex point in Sketch146 to construction.

Select Direction2 for the sweep.

Also,for better control of where the sweep starts, I think the start point of the sweep curve should always be at the same location as the sweep sketch and on the same plane as the sweep sketch.  So, change the helix start angle to 270 degrees.

I didn't follow exactly the dimension what is in the sketch. I have my own dimensions. Because you didn't give any reference to the model.