Its probably not that well known, which might question its validity in civ div, although with NEBOSH behined it you cant go far wrong. What particular are you finding hard? PM me if you need assistance and I will help where I can (also interested in the details of this - might check it out for my own resetlement)
I did it 5 or 6 years ago with HASTAM and got one of only 3 "Distinctions" awarded that year - really good course and well delivered. It is becoming more popular with employers as they begin to take their EP rsponsibilities more seriously.
The exam is typical NEBOSH and requires questions to be answered in their style. If not answered as per their marking guide, they probably won't award the marks (even though the are buried in your answer somewhere). The audit part is pretty straight forward and, if you follow the audit guidance booklet, you can't go far wrong.
Anyway, PM me if you want any further info and I'll try to help (although it was quite a while ago!!!).