Even if it wasn’t a difficult topic like societal problems.
Even if it weren’t difficult content like societal problems.
Even if it wasn’t a difficult topic like societal problems.
無かったとしてもは “even if it wasn’t” です。 “topic” (内容)は複数ではないので “wasn’t” を使います。
Even if it weren’t difficult content like societal problems.
これは同じ意味ですが、違う言い方です。 “Content” (内容) は複数と単数ですから “wasn’t” と “weren’t”がどっちも使えます。
おそらく、しずかさんは「After I finally became skilled enough to talk to you, I realize I still couldn’t find the words to say my own opinion about things. For example, even if it wasn’t a difficult topic like societal problems. So I started practicing writing my own opinions in English.”を言いたいです。