Even though I say I'm studying, I've only been teaching myself for half a year
Although I say I'm studying, It's only been half a year.
「勉強してるといっても自分で半年学んでるだけ」は英語で「Even though I say I'm studying, I've only been teaching myself for half a year.」という表現が良いと思います。
「といっても」には英語で「Even though I say・Although I say」という意味があります。「Although one might say」という意味もあります。
例文
「誰が何と言っても聴かない。」
No matter what anyone might say, she won't listen.
「彼女は歌手といってもお粗末なものだ。」
Although you can say she is a singer, she is very bad at it.