Hi Pete,
I recall those night fears. I found they were worse if I'd had alcohol. It may seem ridiculous to some but I stopped drinking alcohol altogether for 6 months including months after surgery. I would never have believed it possible but actually it wasn't difficult. I now only drink a couple of nights a week.
I also found at the beginning I'd awake and feel alright, then get a sudden fear that something was wrong and I didn't know what it was, then it came back. After a short period that stopped. Although the whole episode of diagnosis is a trial from scan to scan and waiting for results. When I decided what I wanted it began to change to eagerness to get there. When the op date arrived I was actually excited to have a date and not too far away. So it's a roller coaster, not one you'd want, but you need to be focussed and know what you want and have to do.
I felt I was lucky to have gone to the GP when I did and lucky he found it when I hadn't asked him to. My diagnosis went slower than it should but the surgeon made it up and that was also a stroke of luck through a chance remark I made. It helps to feel some good luck I found.
I sometimes wonder if I worried too much and jumped into a decision, some are fairly relaxed and willing to wait and explore options. There is often time I now know, although my case was upgraded after the op and I was told it was near the edge which didn't sound good.
So when you get your diagnosis say what it is and you'll likely get some good advice although your own mind and tolerance of anxiety is often the best for your choices.
All the best
Peter