I was prescribed dilaudid (an opiate) first about 4 years ago to help manage my lung and back pain related to my cancer. I have 2mg tabs with a prescription saying to take "1-2 every 4 hours as needed", although once I had been taking then awhile my doc did say I could take 3-4 on occasion if I had particularly bad pain. In actuality I take 1-2 so I can fall asleep at night and usually wake in the middle of the night needing another to go back to sleep. During the day I take Tylenol (my stomach can't handle the ibuprofen anymore) except on the occasion I have a lot of pain then I will take a dilaudid. I definitely have developed some tolerance - when I first took dilaudid it put me to sleep and if I had to get up to go to the bathroom I was dizzy a bit and had to walk with a hand on the wall... this didn't last long though and now taking one doesn't make me feel different except to take the edge off my pain. I have been careful to take the bare minimum needed to sleep and be reasonably comfortable with the idea it will slow down any tolerance building hopefully. After 4 years though the dilaudid still works, I had to take a bit more for awhile after my brain surgery but now I'm back to 2-3 a night.
My advice is to come up with a plan to manage your pain with your doc that you feel comfortable with. For example I don't typically take dilaudid during the day because I want to be more alert and do things like drive. Staying on top of pain management can be a huge life quality issue though, it's important to be able to sleep and I think keeping pain at a tolerable level makes life much better! I tried to tough the chronic pain out at first it was miserable and a terrible idea for me at least lol.
I can be a bit OCD which I think contributes to my paranoia about any health related symptoms... I report whatever I'm feeling to my doctors and if something is really bothering me I might emphasize that. In the end though I know I have great doctors and I try my best to be patient and let them do their job. But you are not alone in getting anxious about whatever little symptom or every scan!
It's definitely tough when scans or the next step isn't clear, I have had my share of scans where the doc told me to wait and see... then next scan things grow and was back to treatment for me! Wish you the best.