Extraordinary, you have built a continually improving series, found an audience and built up to the point where you have a real hit on your hands, a $10 game that despite being a paid title is the single most viewed game on itch.io right now and that is jaw dropping given this is a site with over a million games. Congrats! If you want a big collection of generally useful textures or a big pack of 3d models, you can buy some of my stuff on the cheap on my itch page as I have a sale ending fairly soon but still active right now, or maybe reply, comment if you, say, even want a few specific 3d objects custom made specifically for you for a little bit under US minimum wage, say $6/hr, feel free to contact me about it. Might be helpful in dealing with the challenges of whatever you attempt next.
-Matthew Hornbostel, matthornb.itch.io