School/college anxiety

I have struggled with the idea of school almost my whole life. When I was in elementary, I had dyslexia (that I still obviously have now) but they couldn't understand my learning disability for a long time and didn't officially diagnose me with it until 3rd grade. This of course resulted in feelings of in superiority among my other classmates. But as you are young you don't really notice that it takes a toll on your grade as well as your time and effort that you have to put in compared to the other people in your class. Growing up and realizing this has made me put extreme unhealthy amounts of pressure on my self to succeed, often putting my self worth into my academic sufficiency. I started college last year and am in my second semester of my first year, and school is definitely a big source of stress for me. Last semester I was taking a stats course and the teacher really sucked and I had failed a quiz that I had studied basically night and day for. It really threw me for a loop and I couldn't stop crying and stressing about the whole situation. To a point where I was not eating and not sleeping so I decided that this teacher was making it way too stressful for me than I could healthy handle and dropped the course. Ever since then my stress for every single course following has been greatly increased. My late Start courses have just started and I am feeling very stressed about the amount of work and my ability levels, looking over each syllabus multiple times and having running racing obsessive thoughts over it. Basically acting as if I had to finish all that work by the next morning. My family has comforted me and offered more help in 10 fold with my courses and it calmed me a little but I still feel very overwhelmed. And I know that if I fail a course it doesn't matter at all and I could just take it again it's not life or death but my mind is making me think it is. Anytime someone even mentions school around me I get a rush of anxiety. My friends talk about doing bad in a class so casually and regularly like its a part of life and it doest really matter and I need to know how to do that. I wish so much that I could break this importance that I put on school and realize its not that big of a deal but I just can't seem to lift the pressure off of me. I am desperate for relief from this and am open to advice and suggestions of any kind from someone that has also dealt with this before.