when you don't care anything else because you're into sth (i.e. baby) but don't want to sound rude: "I can't care anything else but my baby" came to my mind but I want to say that in a more joking way
I’m so immersed in ○○ that I don’t care about anything else.
I've become so immersed in ○○ that I don’t care about anything else.
「○○に夢中」は英語で「immersed in ○○」と「obsessed with ○○」で表現できます。
例:
「勉強に夢中」 → 「immersed in studying」
「料理に夢中」 → 「immersed in cooking」
「この本に夢中」→ 「immersed in this book」
「○○はどうでもいい」は「don’t care about ○○」
「他のこと」→「anything else」
全部まとめて:
「○○に夢中でほかの事はどうでもよくなっちゃう」→
「I’m so immersed in ○○ that I don’t care about anything else」
ご参考になれば幸いです。