I'd say, register for next year, but take it slowly! There are of course other considerations like being able to do so financially, spreading out your course load.

Keep busy, but don't stress or overexcite. Maybe find a dull, relatively easy job that helps you to find some distraction while maintaining a routine. Do you work alongside your studies at the moment?

In my experience, this really helps, counterintuitive as it may seem. I went into mania (or maybe mania take-off preceded it) when I stopped my job, while at university.