Hi Annabelle,
Your time line is similar to mine though this is my second cancer episide after ten years disease free. I don't think most doctors dole out CTs like lollies, is this your oncologist or your GP? If they think more tests are warranted, I'd think hard before refusing.
Pain and anxiety are all part of the process. It can send you a bit mental and you start questioning your own judgement. Yet more reasons none of us want to do this shit. That said, I don't think anyone who is reading your post would dismiss your concerns. Too many of us have had late diagnosis of primary or secondary disease; if you think something is wrong that needs to be followed up.
Depending on where you live, a Pet scan may be an option. There really is no consistency with tests, some of us have bone scans and MRIs, some don't. It seems to depend on what is regionally available and what Medicare will cover (which can vary depending on the stage of your disease)
Keep asking questions. There are no stupid ones.
Marg