Check out Khan Academy videos..they really break down the concepts well. Also, making diagrams and charts helped me a ton to visualize the process and different proteins involved. All the best!

The Krebs cycle can seem really complicated at first. Focus on one step at a time and understand what’s happening to the molecule at each step. Write out the reactants and products to keep track of everything. Over time it’ll come together! Don’t stress too much, you’ve got this

All the best for your preparations! Keep at it, you’ll do great in your arrears exam. Just focus on understanding the key concepts for now, don’t get overwhelmed by too many details. PM me if you need any more help.