Saying "struggle" in nihongo

Recently I had the chance to participate in a japanese teachers reunion (as a student though). While talking to a japanese teacher from Saitama, everything was going fine untill the point were she asked me if there was anything I found hard in japanese at my actual level.

At that point I really felt the need to say "I'm struggling to comprehend the slangs used by japanese in a casual conversation"
I ended up just saying a "いま、普通に使っている日本語は分かりにくい、私にあ ﾆって" , it felt unsatisfying though,

Now, as a matter of improving my own knowledge and taking away this doubt out of my head. Is there an equivalent to "Struggle" (suru verb or not) in japanese?

Thanks

苦労する

口語的な日本語を理解するのに苦労する。