File too big - lagging

Wondering if anyone can help me with a query.
I am trying to append an asset I made the other day to another project of mine. I am quite new to this and when I am appending it the lag is unbearable.

I want to append it with all my texture connected.
Currently the file is 507.7 mb, I then condensed it, however this has only gone down to 376.9mb.

Is there any way I can condense this further? I have tried exporting it both as OBJ and FBX, but the textures do not seem to match up.

Any help would be much appreciated :slight_smile: Thank you!