Bacterial infection in my nose, now headache for 5 weeks. Thoughts?

Hi guys, so I’ve had a headache for around 5 weeks now, that feels like a band around the back of my head. I’ve got a abit of a stiff neck, jaw pain and ear pressure too. Generally difficult to concentrate and do my work.
To give a brief history, around 6 weeks ago I developed what the doctor thought was a small bacterial infection in my nose. I was started on an antibiotic cream which I took for a week. Cleared this up so I was told but on day 3 a headache developed and wouldn’t go. I assumed this was a side effect of the nasal cream but was told this wasn’t. So I worried maybe the infection has spread which is obviously pretty serious if it has.
I went back to the GP, (different doctor) who told me the infection looked to have cleared up, but I may have developed secondary sinusitis and it would take a couple weeks to go.
Last week I then went back to the GP (now a third doctor) who said I don’t have sinusitis but he doesn’t know what’s causing the headache, but was reluctant to offer any kind of scan or blood test and instead I was told to “wait and see” again..

I’ve started to wonder if it’s jaw related? If I’m potentially clenching my jaw in my sleep and this is causing muscle pain and the headaches. So I’ve got an app at my dentist next week..

But I’m honestly at my wits end and I think by now I need a scan or something to figure out what’s causing it.
Should I call back and demand a scan?
Does this sound like anything to be worried about or any ideas what it could potentially be?