What do I do with my lemon eucalyptus?

What do I do with my lemon eucalyptus?

Hi guys, I have a tiny bit of a problem regarding how I should deal with my lemon eucalyptus. I live in a flat/apartment. That means a severe lack of space. My lemon eucalyptus has grown so tall on the ledge I placed it at that I don't know what to do with it now. Its tips are touching the ceiling; problem is I have absolutely no more space to shift it around with. Should I prune it? Will pruning stunt the growth after that? Someone suggests that I should bonsai it. But I'm not sure if it'd take to bonsai-ing after almost a year of unchecked growth. For reference, two pictures:
A little bit of pretty

A little bit of pretty

Calandiva

Calandiva

Plant ID

Plant ID

buds and seeds

buds and seeds

New kitchen for me

New kitchen for me

My roooommm

My roooommm