Reduce library size in Final Cut Pro

I am not even sure if I am using Libraries, Events and Projects correctly but I am slowly learning. Currently my workflow is to put raw footage on an 1TB external SSD. The library is also stored there. I transcode the media from h.264 to AppleProRes (Hopefully I am saying this correctly) and edit the video. I was transcoding some footage today and I got the warning that my storage space is running out and that I need to make room if I want to continue. So I moved a bunch of footage from that drive to another but still I am not gaining much ground here. Come to find out, the FCPX library file (.fcpbundle) is huge (720.86 GB) . It is taking up about 3/4 of the space on the 1TB drive. So I moved some Events from within the library to another library thinking this would reduce the size of the library. it did not. So hence my question. How in the heck do I reduce the size of this library so I can work off this drive?

Should the library be on a different drive? If so, How do I move that without FCPX not loosing track of where the original footage is?

Many thanks,

Houston