Don't worry too much about not being able to stretch as fast as you did before. 4 - 5 weeks is a rather short amount of time to wait between stretches, but it's also not uncommon for people to stretch faster. Everyone is different, but the normal time frame would be 2 months or more for certain people.
Ear stretching takes a lot of patience to do properly. So remember to not rush it.
As for the spiral tapers that you are currently using...I wouldn't advice you wearing them all day or to sleep as you're risking your ears ripping by the spirals getting caught on something. Tapers are always only used as a stretching device, and should never be worn as a jewelry piece. The common spiral ear hangers are fashion pieces that are not worn extensively, or shouldn't be for exactly the same reason of risking your ears ripping.
Hope this helps!