Welcome, Artsygal!
I remember your intro... it struck a chord with me. You've been on a path that could very easily been my daughter's (she's 18). She's a Christian as well and struggles with the hypersexual side of cyclothymia when she's hypomanic... so she lives with some of the same feelings, I think. Her psychologist also recently diagnosed me with a mood disorder, as well as my husband with cyclothymia. THREE moody people in one household, isn't that fun?

I wish I'd known years ago that what I thought was normal teen angst (in myself) and normal female moodiness (again, myself) wasn't. It was only through the knowledge I gained through my daughter's disorder that I started putting things together. Kind of a Oh wow, Lightbulb moment. I didn't voice my suspicions, but through seeing some of my writings and doing some marriage counseling with the psychologist as well, he came to the same conclusions entirely on his own. Now I understand WHY and that it's not normal and can seek help. From counseling, maybe meds.
Anyway.... You didn't ask about all that.

What you DID ask... let me start by saying while I've had a couple of years to read a LOT on the subject, and see my daughter's treatment and my own... I'm not a doctor. So these are my thoughts, not those of a professional!
You mentioned your grandma was dx'd as manic depressive and wondered if that was the old term for cyclo. Not exactly, but sort of.

Manic Depressive is the old term for what is now usually called Bipolar. Bipolar is really a spectrum disorder, meaning there are different severities/presentations/symptoms. Cyclothymia, most would say, is a form of bipolar (others are Bipolar I and Bipolar II). When our psychologist diagnosed my daughter he indicated that the reason she would be cyclo rather than bipolar II is that her lows weren't as severe. So... your g'ma did have bipolar and you have a form of that - based on your doctor's evaluations, not mine!

Does that make sense?
Meds and diagnosis -- if meds are helping, then I would say it certainly looks like your pdoc is on the right track. To counter that, if they are not working, though, it doesn't mean that your dx is wrong, just that he hasn't stumbled on the right drug combination for you. And I certainly wouldn't say your positive reactions indicate an addictive reaction. There can be withdrawal symptoms if the drug is stopped abruptly, but it's not truly addictive. My husband was on tegretol for years for epilepsy. When it looked like he was growing out of the epilepsy, they reduced his doses rather than stopping cold turkey. The drug was controlling symptoms that they didn't want to throw him back into. It's basically the same when it's being used for mood disorders. Your symptoms are being controlled, removing the control suddenly is a bad idea.

And... a word of warning... it's pretty typical for those on the bipolar spectrum to get feeling good while on their medications and think they don't need them anymore... next thing you know they've stopped taking them and the symptoms return. Be careful about stopping meds, especially without a doctor's supervision. Always stay in communication with your doctors
As far as natural options... it sounds like you've been down that road unsuccessfully and the meds are helping to stabilize you now. Personally, I don't think I'd mess with that. Let yourself be helped. I am in the beginning stages of diabetes. Several years ago I saw it and went down the natural road for awhile -- more care in my diet, more exercise. It worked for awhile, kept my blood sugar levels within normal. But they've started creeping back up and I'm afraid I'm coming up on a point where that may not be true anymore and I may have to accept that medications are necessary. If I am at that point... no one who understands the disease would try to suggest that I don't need the pharmaceuticals. It's no different with mood disorders. It's a chemical imbalance in your body that is a real medical issue. If natural methods have been unsuccessful, don't deny yourself the help just because it's not "natural."
Again, just my thoughts.... hope it helps!