I had the same concerns as you until about a week ago. I’ve been studying from this book for about a week and I already feel much better about navigating the reference book. The problems have been updated for the CBT such that all the solutions use equations from the reference book. I may be able to sell you a copy below market rate after May 21st (my exam date) - let me know if interested.
Sorry to hear that you did not pass, but hopefully this experience helps you out the next time. I do agree, there's VERY little practice for qualitative problems or ways to prepare for them. I did find that the PPI Practice Problems booklet had a fair bit of practice but still not a ton. https://www.amazon.com/Environmental-Practice-Exams-Wane-Schneiter/dp/1591265746
Good luck for the next round! Give yourself a break before getting back at it.
I used this for practice questions: https://www.amazon.com/Environmental-Practice-Exams-Wane-Schneiter/dp/1591265746
I also used the Lindeberg review books. I found them helpful in providing background on topics I wasn’t familiar with: https://www.amazon.com/PE-Environmental-Review-Michael-Lindeburg/dp/1591265754/ref=pd_aw_fbt_img_sccl_2/135-9088028-9577154?pd_rd_w=Dp2Ip&content-id=amzn1.sym.f353d175-26fc-4776-8298-842dab47b290&pf_rd_p=f353d175-26fc-4776-8298-842dab47b29...