After three different attempts of my exam crashing (test by vue) I failed it.

I feel discouraged because I have been studying for several months now. The test was pretty fair. I got one router sim; OSPF and I forgot to delete the routes that were already configured. After I realized what I forgot to do my mood completly changed because I knew I was done. I had a couple of drag and drops and lots of troubleshooting questions too.
I wonder what I am doing wrong. I have been studying from two books Cisco Press and Sybex and the sad part about it was that I thought I was ready. After failing the test I know I have to re-take it but I don't feel like it. However, I have to bounce back and hit the books again
Are there any good OSPF sims out there?