It just sounds like you tried a little too much too fast, especially with the nem..... You're actually better off sticking with the 55 rather than going down to a 28 or 29 nano/bio cube. The larger water volume affords you some more stability. If you think you're having problems with a 55, it would be twice as bad with half the volume.... trust me, I tried it. Working in construction, I put in some long hours as well. When you have a really long day, sometimes the last thing you feel like doing is working on your tank, and you absolutely cannot neglect a smaller tank. I wound up building a rescue tank with a sump system in the basement just to save what was in my nano, and after it fully establishes, I'll be tying the nano (or larger) back into the system.
Wanna calculate the cost of that new reef tank?? Take your worst nightmare, double it, and you're halfway there.