I have some Hungarian Black Pepper plants, and so far I've lost one and am probably going to lose a second. They've been attacked by aphids indoors recently and I'm wondering if this has anything to do with it. For example, maybe the aphid damage is causing them to lose moisture?

The lower stems also seem to be shriveling though which might point at a different problem. Could this be a fungal attack, and is there anything I can do for the last pepper? Or maybe it's not planted deeply enough and the hypocotyl is sticking out?