I get this all the time and I just have to remind myself that there is effectively an endless supply of paper, canvases can be repainted over and over.
easy: I paid for a useable item not a fancy desk ornament. this is why I buy cheap or practical sketchbooks. honestly it just goes to waste and is a mindset you gotta break over time. I have no problems now because I've tired so many student and artist grade supplies, everything is sorta the same and one might feel slightly nicer but rarely does it really
make much of a difference unless it's watercolor paper - that is one supply that quality and style of paper counts , and gouache paints. all other supplies it's not a huge deal of it's expensive or cheap
also I have about 3 "trash" sketchbooks that aren't filled with pretty drawings. many have random doodles and writing in them, ones that are super cheap, that I fill when I just wanna play with a pencil. it sorta helps you warm up for when you wanna sketch more serious
and also... you won't ruin it, it's legit job is to be USED. it won't be offended if you don't put a perfect drawing in it... it will be offended if you keep it blank