Home treatment for seborrheic dermatitis?

[Izera]

15 years ago I developed seborrheic dermatitis in my ears and my groin.  The first doctor prescribed a steroid cream and told me to wash my hair with dandruff shampoo and put a little of the suds in my ears and on my groin.  The steroid cream worked for a couple of weeks and then stopped.  A few years later a second doctor gave me samples of an anti-fungal cream and told me to use it.  That did nothing.

So basically I've been itching non-stop and clawing my body up pretty good for 15 years.  And it spread to my face a couple of years ago, making me more miserable.

I'm now developing more spots on my chest and near my belly button.  About a week and a half ago I googled home treatments.  I tried a dandruff shampoo that contains zinc pyrithione, but this time I rubbed the shampoo directly on the spots instead of just the foam.  My ears and groin are still red but the scales and scabs are virtually gone in less than 10 days and I only itch when the skin is wet (sweat or post-shower).

Hey, this works.  And I'm tired of itching.  And now parts of my scalp are itching, on top of the ears, face, chest, belly area and groin.  So yesterday I bought a second dandruff shampoo with selenium sulfide, athlete's foot cream and cortisone cream.  I'm planning on using both shampoos when I shower, first one, let it sit a bit, rinse off and then the other.  I'm planning on using the athlete's foot cream and the cortisone cream twice a day.

Is google right that this will work to get this under control?  Is there more I can do?  I can't spend the rest of my life this way.

Doctors are not an option.  I've got the insurance, I've got the money.  But after two doctors failing miserably with the seborrheic dermatitis and recent experiences with seeing a doctor only to be told of OTC stuff to try instead of prescription treatment, I don't feel like wasting my money.