Is Personal Injury this rough?

Hello! Recently started my first paralegal job at a Plaintiff Personal Injury firm. And the first week was great... Then this week they threw a bunch of cases on me because someone is quitting & training pretty much no hands on training so I've been winging everything and feel super unorganized. I'm already staying a hour or two of OT a day already because none of these cases have anything done and a lot of them have been sitting for 6 months+. I only have had three cases which started with me and I'm organizing them and preparing them because they are my cases but it seems like my manager wants to throw a lot of other people's issues and work on me that I have to fix and it's just starting to stress me out. Any advice?