Why are my illustrator files so big?!

Recently my illustrator files seem to be getting larger and larger, to the point that they are taking around 4-6 minutes to save and are slowing down my laptop.

I am a fashion student and create several garment spec drawings per week and need to be able to open and edit them often. I have never had problems like this, I cannot share these files with anyone via email, even after exporting them as a TIFF. The files are averaging at 160MB for something basic and going up to 360MB for something with several clipping masks. It is completely unmanagable. I have no idea why this is happening or how to fix it but I really need help.

I cannot use files that are this big. It just crashes my laptop every single time I open more than 4/5 files.