Theres a whole department of Mechanical engineering that deals just in springs and material characteristics. We did some calculations in college and some theory but i hardly remember anything.
Some links for reading that might help you:
Deformation in general: https://en.wikipedia.org/wiki/Deformation_(physics)
Hooke`s Law ( you are dealing with linear springs) : https://en.wikipedia.org/wiki/Hooke%27s_law
Plasticity : https://en.wikipedia.org/wiki/Plasticity_(physics)
Elasticity : https://en.wikipedia.org/wiki/Elasticity_(physics)
How to draw a Hooke`s Diagram for your spring : https://www.edrawmax.com/article/a-guid…th-diagram.html.
Just an idea,maybe the best thing would be to contact a university to provide some tips/guidelines on solving your spring problem ?
I can check my Mechanical Engineering Manual when i get home to see if there is anything usefull for you in there if youd like that.