Reduce file size for artwork file

[Lizz5C4F]

I have a very large artwork file for a textile print that I'm working on and now that the artwork is done the file is extremely slow. Even when I try to rasterize it the file is very slow. Unfortunately rasterizibg it makes to artwork loose quality and I need it to be high quality for the printer. Right now the file is about 300 MB. How can I make this file smaller so that I can work with it without it freezing?

[Monika Gause]

What's in the file?

We need to know the functions you use. 

[Lizz5C4F]

It's a water color floral so there are gradients and paint brushes and bristles brushes 

[Monika Gause]

Then probably there is little chance to make it smaller.