Surviving class

I am in a biology and chemistry class. I keep wondering if this was a smart idea, especially since it's been so long since I've taken a science class. The last time I took biology was my freshman year of college (back in 2003) and because of where I was mentally, i pretty much gave up on life, school and pretty much everything in between. I think this has been a big reason I haven't attempted any science before this semester or even going to nursing school. Anyway, we were doing the basics in lab today since it's still the beginning of the semester. I did my assignments and walked past some instruments. Razors were out on the cart, just laying there. Memories came flooding back into my mind, and the shame seemed more than I could handle. I about had a panic attack in the middle of class. How do I function on a day-to-day basis when even looking at a blade is a trigger for me? It'll work out, just not completely sure how.