I'd guess one of two things--watering too much or not giving it enough light. The former is the most likely culprit. I don't like to think about how many passis I drowned to death when I was starting out.

Maypop can drop leaves and go dormant if the day length is too short or light levels too low, and temps somewhat cool. Only water it rarely to keep the soil from becoming extremely dry, and keep it in a cool spot, and the roots should be fine until spring. If you can give it good light for 14+ hours a day, and keep the roots warm, it should start "popping" up new shoots.

My lavender lady has dropped all of its leaves (well, almost) each winter ever since I got it (5 years+ now). Right next to it Vitifolia full of leaves, Incense new growth and plenty of leaves and Capsularis (nice and full).

Coral glow (half of the leaves are curled, the rest look perfect) and Caerulea (lost all the leaves on the sunny side, the non-sunny side still has leaves and new growth...I dare not turn it again!)

Some of them are just funny and tempermental. Water sparingly and no fertilizer til after the first day of spring. (well, that's what I do)

~Chills

I've found that indoors they live on neglect. I don't know how many times I've looked at mine & noticed all the leaves drooping.. Lifted the pot & by weight it must be dry as a bone.. "Oh Crap!" rush to the sink for some water, which runs right through the dirt's so dry..

Yeah, that happens about every 2 to 3 weeks.

They're not terribly happy, but hey- they're alive when it's freezing outside.

Ok. Deep breath. You are all right. I'm probably overwatering (I had stopped dumping water on it a week ago, ha ha), and it doesn't have a lot of light (no more than the winter light, but it's a south facing window). It still has one green twig still alive, so I will cut the watering. I'll have to get some lights on it as well, hopefully that will keep it from dying. We shall see! :) Thanks for helping me feel better, I hate killing plants.