need help with sims

in CCNA & CCENT
Hi all,
I have taken the exam twice but failed because I got the sims wrong for both my tries
.The sims are really confusing. Although I have practiced a lot but I don't know what goes wrong in the exam. Please suggest me where from can I practice more for simultaions. Is it that the simultaions are far more tricky than difficult?
I really don't feel like taking the exam unless I am confident about the sims. Please help me.
Thanks
I have taken the exam twice but failed because I got the sims wrong for both my tries

I really don't feel like taking the exam unless I am confident about the sims. Please help me.
Thanks