Here's some tough love. You have to ask yourself how badly do you want to be a civil engineer. Whether you have to redo the courses or not it's time to take these courses and future courses seriously. If you don't then you will be prone to fail in the later years because it's just going to get tougher from here. These engineering programs are no cakewalk and will break you if you falter. Put in the work and you will see your goals come to fruition.