Estella,
No, transformed Migraine (TM) shouldn't be permanent. With the right treatment, you should be able to resolve it to episodic Migraine of whatever type of Migraine you have -- Migraine with aura, Migraine without aura, etc.
Medication overuse is a factor in 80% of cases of TM. If medication overuse is a factor, resolving it is the first step. The amount of time to resolve medication overuse headache depends on the type of medication that was overused, whether it was one medication or more, how long those medications were overused, and how your body reacts. It can take weeks or months.
Once medication overuse is resolved, or when it was NOT a factor, the key is finding and resolving any other factors leading to TM, then finding an effective preventive regimen.
Sleep issues can also contribute to TM. How are your sleep patterns and quality of sleep?
Here are some articles that should be helpful:
• Transformed Migraine - The Basics
• Stopping Medication Overuse Headache Can Halt Transformed Migraine
• Trasformed Migraine Related To Sleep Problems
Teri