Overture: Stuck in Chemical Storage

[tinibutton]

Hello,
I'm new to the forums and am hoping someone can help me. I just recently went into the Chemical Storage for the first time and the worm scared the crap out of me! I ran and did not see the first door switch on the left, I quickly hopped across the crates and stood in the next room in front of the wooden barrier, figuring the worm would get stuck in the acid (which it did). It didn't seem to die but it stayed writhing in the acid, creeping me out so I pushed the switch and closed the doors.

I went through the next room gathering all the chemicals I could find, and left before I realized I forgot chemical C. Now I've tried to return multiple times but once I go into the hall where the worm attacks, I'm stuck. I can't open the main door once it closes behind me, and the second door that I shut is still closed, trapping me in. The first switch is green but does nothing when I switch it to red.

Thank you to anyone who has any suggestions!
~ Mandi