Breakdown of monthly helpdesk tickets

[Tholmes]

I have 6 types of tickets, Onboarding and offboarding, IT purchase, Infrastructure IT Support and project.
For all the other tickets I can easily tell why calls are slightly higher or lower, but the IT support one we have differences of 60-100 per month.
I want to be able to just break it down, we have 13 headings under IT support, how can I just run a report against those and just have the subheading from below come up?
I am a SQL dummy, I can bodge things together and sometimes make them work but I think this requires knowledge and finesse, SQL skills I am severely lacking.

I have this script that I thought I could modify to add the additional info from IT support, but I don't have the ability to amend to this code.

,
Select Top 1000000 DatePart(yyyy, htblticket.date) As Year,
DatePart(mm, htblticket.date) As Month,
htbltickettypes.typename Type,
htblusers.name As AssignedAgent,
Count(htblticket.ticketid) As TicketCount
From htblticket
Inner Join htblagents On htblagents.agentid = htblticket.agentid
Inner Join htblusers On htblusers.userid = htblagents.userid
Inner Join htbltickettypes On htbltickettypes.tickettypeid =
htblticket.tickettypeid
Group By DatePart(yyyy, htblticket.date),
DatePart(mm, htblticket.date),
htbltickettypes.typename,
htblusers.name
Order By Year Desc,
Month Desc,
Type,
AssignedAgent

I tried modifying this script from here, but failed miserably.
Could anyone show me the light please?
As always, thanks in advance.
Tim