Ok, now we know where you are. Your plant is hardy and must be outside all the time. In the winter if it gets very cold then in a cold unheated greenhouse. But not indoors. It is time for hard pruning and re potting. The plant will die because you are not giving the right conditions, the mites are not a problem, your culture is.
Water when just dry you need to check the soil every day and water when needed. Don;t water to a schedule.
The plant does not look like it is dying yet, if you change the way you are treating it then it will recover.
