Afid on catnip?

[gossamer]

I have two indoor catnip plants that I moved from outside when it got cold here in northern NJ (zone 5) in late Oct. They were both growing well for a while, but about a quarter of the leaves on one of the plants started to look like it was becoming moldy, as if it was being overwatered. So I stopped watering both of them for about two weeks.

Now I'm noticing the undersides of the leaves have a small bug, like an afid, that has attached to about 20% of the leaves. Are these plants salvageable? Will an insect spray save them?

 

[MiTmite9]

That second photo is showing powdery mildew. You can use milk and spray the leaves. That may help. The third photo is showing thrips.
For the mildew:

For the thrips:

---- start this video at 1:30 to get to thrip control

 

[gossamer]

very helpful. Thanks so much for your help.