I can be the same way about a lot of things, so I say this in a friendly tone: just do what you want. Seems like you really enjoy browsing the bookstore with your coffee. You say sadly, and call it a bad habit, but it sounds a really pleasant way to spend some time! Your TBR stack is just a pile of inanimate objects. Don't let that pile rule over you and how you spend your time. You don't owe the books anything, and no one is keeping track of if you have a big stack of books or not. You do not have a duty to read those books.

Unless buying books is putting you in serious financial trouble, there's nothing wrong with what you're doing.