“Philosophy [nature] is written in that great book which ever is before our eyes -- I mean the universe -- but we cannot understand it if we do not first learn the language and grasp the symbols in which it is written. The book is written in mathematical language, without whose help it is impossible to comprehend a single word of it; without which one wanders in vain through a dark labyrinth.”
Galileo Galilei
Remember our goal is to become literate in the language of mathematics.  Keep your focus on understanding the concepts and not simply on "doing problems". 
Don't waste the opportunity you have to achieve greatness.  When the material becomes difficult for you, use a resource.  We all get stuck.  What are you doing to get unstuck?
"In the Abundance of Water, the Fool is Thirsty."
Bob Marley