I don't think you're doing too much. You need to do what works for you to learn the information. You need to look at why you failed before - what were you NOT doing that you should have been, or what could help you now that you were NOT doing before?
My best advice for studying (which is the method I used when I was in school and it worked great for me):
Look at the syllabus...read the chapter(s) that you are going to go over in class BEFORE going to class. Take some of your own notes, but don't focus too much on the notes. Just read the chapter(s), get yourself familiar with the info. (it's hard to take notes if you don't know the info - if you don't know the info, then you'll think everything is important and be writing waaaay too much. If you have at least a little idea of the info, you can at least get kind of an idea of what is important and where to start). Again - read the chapter(s) before class. Take some of your own notes, but don't focus so much on that. Focus mostly on reading the chapter(s) and getting a handle on what will be discussed in class. If your instructor posts powerpoints...just use that to make little notes while reading the chapter(s) (maybe something you want to ask your instructor about during lecture, maybe something you don't really understand yet and want to focus more on later, etc.). I know some instructors pass out printed powerpoint lectures, but don't do it until the day of class and don't post them online. So if that is the case, don't worry about it. Again, the important thing is just to read the chapter(s) and get a handle on what will be discussed in class.
DAY OF CLASS:
TAKE NOTES!! Take lots of notes. Don't be afraid to ask questions - ask as many as you need, talk to the instructor after class if you need to. Don't worry about the notes looking good (we'll worry about that later) - Just scribble down everything you need to. (my notes were a mess after class - I would write them fast and think of things after the fact and make notes on the sides and squish something between other things)
If possible, right after class (or as soon as you can but try not to wait)...type up your notes from class make them well-organized. Fill in anything you left blank, use your book to supplement things, add to things that you didn't understand, find examples in your book that help you understand, etc. Make this as neat as possible. This is what you will use as your study guide. Read through it, write it out over and over again, whatever helps you retain the information best. (Personally, I need to write things out in order for them to stick in my head, so I would type up the notes nice and neat, then I would write em out over and over again until I felt I had a good handle on them).
Now...when I took notes...I tended to end u with PAGES! So, after I had spent time studying them and studying them and studying them and learned everything I could from it, studying them all was just wasting time because I learned all I could from those notes, so I would go on to my final step. Of course, there was always some things from those PAGES of notes that I had a hard time with still. So, I would take a piece of paper, then I would take the key concepts from those PAGES of notes and I would write just a few words or something to remind me about each one. You are only putting in what you DON'T KNOW. This ends up breaking our notes down from everything to only what you still need to review before the exam. The key here is to not go over 1 page. If you have, then you have put too much information – either you haven't learned everything you can from the PAGES of notes, or you just didn't condense the info enough. So, if you need to, go back and review those PAGES. If not, just focus on condensing what you have down more.
Doing this helped me actually RETAIN the information. I didn't just cram it into my head for the exam and then forget about it to learn the stuff for the next exam – because then, I would have to review EVERYTHING when it came time for the final exam. Instead, I used this method so I could actually LEARN AND RETAIN everything. So, when it came time for the final exam, I just needed to key concepts and the stuff we just learned.
Good luck with nursing school