I spent a lot of time trying to avoid hurting my H's feelings as well...not, not years like you, we haven't been married nearly as long as some on here have, but still quite a bit of time.
One thing I've learned though when trying to communicate to my H about sex (and not hurt his feelings) is that I cannot go out of my way to not hurt his feelings...if what I have to say is honest and truthful then I can't really help if it hurts him...he will get over that, or it won't hurt him as bad as you fear it will (which has been the case for me).
When I've tried to avoid hurting him I've ended up doing nothing but sending him mixed signals...which I think in the long-run made him think I didn't really think the problem was that big of a deal. Then if I'd finally get upset enough that I'd explode...he'd get confused and probably thought I was hormonal.
Moral to this story? Don't sugar coat it. Be honest and forthright in your conversation...maybe if you need to tell him you want to pick a night to have a conversation you've been needing to have for quite some time. "No honey, I'm not leaving you but we have some serious issues in our R that we need to really discuss and seriously address." Now, if he's anything like my H...you may end up having the conversation right then.
When it came to the point of finally getting my H to the Dr or a C...I had to call him on the carpet telling him his choice of action for solving our problem was "inaction"...and that wasn't acceptable. The problem hadn't magically fixed itself by his course of "inaction" since it was brought up and I couldn't fix it on my own...so obviously we needed to seek professional advise...be it a Dr. or a C.
You may ask your H why he won't go to a Dr. about his ED...what's he afraid of? That they will find a problem? Or that they won't be able to help? Regardless of which it is...isn't it worth having it checked out just because you, the woman he loves and married, are concerned about it and have requested he do this for his own health? That's kind of the approach I had to take to have my H get to a Doc. and have a thorough physical and lab-workup.
For him I had to take the approach of "let's rule out any physical problems. Then if there's nothing physically out of whack we'll go to a C, because if nothing else I need help with learning how to deal with this situation." Of course I knew full well that any C we might talk to was going to see that my H had a gammet of R issues from the past...but it was my way of getting him to someone to talk.
It's a long freakin process I know...but it's what I had to do.
I hope any of this is helpful to you. I hate that your H has ED and won't get checked out...there are so many things that it could be that could be easily fixed for him and it must be so frustrating that he simply won't go.
Would you like me to come hog-tie him? Then we could throw him in the car and drag him off to his Dr.?