Need help with sweep cut

I think a change of method.
I would use mirror at end - this will simplify the sweep cut.
The path for sweep need to change to get the curve at blunt end.
For your sweep - try to sketch the profile "normal" to the path, rather than at an angle.

  1. Step 1:

    Model - as expected?

  2. Step 2:

    The path for sweep - extended beyond the cutting area.

  3. Step 3:

    The profile for cutting - one side only.

  4. Step 4:

    And mirror the body to finish.
    I added a split face to show the temper zones - just because!