Need help troubleshooting leaf problem with potted miniature rose
I got a potted miniature roses plant earlier this year (summer time). I am not good with plants, but after I figured out the right lighting and the right watering schedule, the roses did really well. It was growing a lot and blooming a lot. It was fantastic. The plant sits on a east facing window sill, and I was watering it every day.
Then the weather started to get cooler. I live in Los Angeles, and the temperatures have dropped about 20 or 30 degrees. I began to notice a white fungus on the plant. I did some research online and identified it as powdery mildew. Following what I read online, I cut away the affected areas. Then I bought a garden anti fungus spray. I sprayed the plant once, but the spray was pretty horrible, so I have not used it since. I also thought that maybe the fungus spray burned the leaves.
I also bought some liquid fertilizer and was using that, following the directions.
Ever since the weather turned, the plant has not been doing very well. Because of the cold temperatures, I cut back on watering (every other day now, but that may even be too much, it seems). I have noticed bad things happening with the leaves, and kept cutting away damaged areas. I have cut away a lot of the plant so now it's a lot thinner than it used to be.
I really like this plant and I want to resolve the issues, but I don't know what's wrong. It's not getting as much sunlight as it used to (because it hasn't been sunny or as warm), and I'm not really sure 1) what's wrong exactly, 2) what to do to make my plant "happy."
I would really appreciate any help. I took some pictures to show some of the leaf problems.