have you noticed the colors of building parts changing colors, if you pay attension to it you can build huge houses. you cant just add pieces to structure that is already stressed/red.
also sounds like youve not even explored or been off the first island, i was only hooked after i did the first boss and the new materials opened up a load of different stuff.
also look at the wiki to help you. its stop from getting stuck, i missed unlocking core wood and had no idea what i was missing out on to progress