First of all...you are having surgery. I am sorry, but, I dont care what he is feeling or thinking or if he has PTSD (hate that term...that should be reserved for soldiers who have seen and done the unthinkable). Poor M...not.
Here's the thing. You can think all day long about what he may be feeling or not, and never know...so that's wasted energy right there.
The focus at this moment needs to be on you and your health. Whatever he may or may not be working thru is not your problem...it's his. Leave him to it.
I agree...you are always looking at the other person. You are always worried about whether you are good enough for them. Screw that.
He is either going to figure this out or he isnt. There isnt anything you can say or do that is going to change that.
What has to change is your thinking. You are making yourself crazy trying to figure out what it is and that isnt healthy.
If this all spooks him then he isnt ready for a serious relationship. Nothing to do with you.
You could be perfect...it's still his issue.
So, let this go, G. Let go of the negative thinking. Let go of taking blame. Let go of thinking how it is going to play out and live your life.