i came to a point where a project file size is around 1gb

now, its possible that this is normal, altho my project is currently not that complex, around 10 layers spread on 200 frames, and only two of them are actual animation and not just stretched.
if its indeed like that in tvpaint, i can handle the the HD space need, the problem is that tvpaint gets really unresponsive when working on a project like that
it just hangs for a few seconds everytime i make specific actions, like choosing a layer, turning a l layer on\off, saving etc... and only getting worse as i go
id like to know if im doing somthing wrong or thats the way its