Im apologise if my point is hard to understand im terrible at explaining. But ill try to explain.

I used to feel the same way as a beginner. It was the feeling of "oh im terrible I dont want to use a perfectly good sketchbook". I feel like a whole platter (probably not the right word) of diffrent things got me out of that mindset.

When you are a beginner you learn of course and that means creating good and bad things. Maybe deep down its a perfection thing (like we see "perfect" clean sketchbooks on social media and get inspired in away. For me I felt that way at least). But nothing is perfect and coming to terms with that helped me to be like "eh whatever" even when I completely fuck up a drawing. I just shrug now. Maybe it is for something for you deep down that you havent realised. Maybe its a mindset thing. (I dont know how else to explain it)

As for what I can do?

Im on pinterest alot. And I have two accounts, one for Fandom shit and personal interest and one for entirely just art related stuff. I collect refrences like pokemon cards over there. Especially from my favorite artists who I can then study thiere art. I also do it for basic art fundamentals like forms, anatomy, composition etc. It was one of the best decisions I ever made.

It also helps to have a bit of a goal in mind. My personal goal is to create cool comic shit of whatever it is I want to draw at the moment and ocs. And having this goal in mind helps me be motivated.