FYI, read the LSO recruitment procedures for 2L. They identify your obligations as a student wishing to participate in OCIs....I believe one of those obligations is to inform all potential firms still considering you when you have accepted an offer. I'd take a look at those rules more specifically and, based on your original post I can tell you that the rules do apply to the region you worked in.
Their website says you will be sent a report in the next few weeks, detailing your performance on each individual section. I’m sure this is a hard bit of news to process, but I would wait to get the report before you plan a strategy going forward. That way you can see where your weak points are. The website also indicates there is a tutoring service set up for those who failed their first attempt.
Ultimately, take a deep breath, wait for the report, and go from there. I don’t think there’s any use in speculating where you went wrong when the LSO is going to tell you