Get this and change your study habits. This book has been suggested on the engineering site and the one book my son didn’t give back to me.
https://www.amazon.com/How-Become-Straight-Student-Unconventional/dp/0767922719/ref=mp_s_a_1_2?ie=UTF8&qid=1546367803&sr=8-2&pi=AC_SX236_SY340_FMwebp_QL65&keywords=cal+newton&dpPl=1&dpID=51mKmt0ltIL&ref=plSrch
(hope I did this correctly)
It is a fun fast read with great suggestions. Many on CC swear on this book and rave about it.
You say you study a lot but that might not be the best approach. Studying efficiently is. This book does that. Do what they say and couple this with your schools learning center and keep going to office hours etc. Peer to peer tutors help and as suggested group studying also.
Also keep in mind that there can be a full grade drop the first semester /year till you figure out what the college professor wants you to learn vs your high school teachers. It’s different.
Find out if you are a visual or auditory learner also. This can help a lot also.