I had an odd nightmare?

a couple months ago i had a disturbing nightmare. i was in a fetal position, cold, weak, and hungry. i remember i was crying, trying to hide from something. i was hidden behind a tall metal wall, maybe behind an abandoned warehouse or something. there was thunder and lightening, and a huge storm brewing. it began to rain really hard, but it wasn't normal rain, it was acid rain. i've never experienced acid rain. the acid rain began melting and eating away at everything, including myself. i screamed out at the pain and began trying to run for cover from the rain. whatever i had been hiding from before was after me again, but they didn't seem affected by the acid rain at all. things get blurry after that. my dream ended when i collapsed from exhaustion and closed my eyes. i woke up after that. what could the dream mean?