How long to get a lung diagnosis and how frequently to chase?

Good evening - I've been browsing the forums for several months but my first post. Hopefully it's in the right place, and apologies if not.

I don't have a diagnosis as yet, the short version of my journey to this point is as below (fuller description in my profile):

I'm an ex smoker in early 50's so assume high risk.

Early Feb:

• Coughed up very small amount of blood - x ray taken and referred for CT.
• CT showed two 4mm nodules and bilateral ground glass changes. Advised for follow up CT in 3 months to see if ground glass had cleared up

End May:

• Getting mild discomfort in left shoulder - really mild and quite possibly muscular/stress/anxiety
• Second CT scan taken

Mid June: 

• At follow up, respiratory consultant said the ground glass hadn't cleared up, however it hadn't grown either. 
• Some small opacities in top of left lung, and a larger opacity in lower right lung
• Since meeting, have started to get discomfort in right hand side now - again, quite possibly muscular/anxiety etc.
• Also seem to have started getting tinnitus in left ear - probably stress/anxiety.
• I was advised that a PET scan would be organised in the following fortnight with a follow up 2 weeks after that (i.e.mid July).

Nothing arrived in the post up until today re the PET scan (and it's been a week), so I've tried calling secretaries and so on, but it's just endless answerphones.

I've got to be honest, I'm not coping very well with the anxiety of it all. I am probably being over dramatic, whilst my partner is very dismissive which causes further anxiety.

I'm working at home permanently these days and whilst it has it's benefits such as allowing me to take the kids to school, it also leaves me alone with my thought for far longer than is healthy I think.

Part of me thinks:

"Well they are not rushing things so in comparison to others' experiences I've read they can't be too worried about what it is",

then the other part of me thinks:

"What if they have missed anything/forgot/just too busy with covid".

Whilst I'm not looking for any medical opinion here, it has been good for me to write it down - helps gather the thoughts.

I know these people are professionals, but letters get lost etc.

Is there any rule of thumb with these appointments?

Would you expect a letter to be sent within a week with a new appointment or is that a bit too quick?

Many thanks for reading and peace to all.

D