I keep buying similar clothes without even realizing it.
I don't mean to, but I keep buying clothes that look a lot alike.
ーI keep buying similar clothes without even realizing it.
「ついつい似た服を買ってしまう」
to buy similar clothes で「似た服を買う」
without even realizing it で「ついつい・いつの間にか」
ーI don't mean to, but I keep buying clothes that look a lot alike.
「ついついよく似た服を買ってしまう」
don't mean to「〜するつもりはない」を使って「ついつい」を表現できます。
ご参考まで！
カナダ 
