10 Gb is insane! I don't think that fiddling with sprites (loading/unloading them) will make much difference.
You definitely need to rethink how you manage animations in your game - significantly reduce their size, use fewer frames, break into modular sprites (see Spriter), use effects instead etc.
I did some tests and it worked fine... And yes the problem mainly is about resolution of frames, I tried reducing them to 50%, it kinda ruined the visual quality. I'm thinking about considering this at the last solution.