I don't think you are being stupid to feel this way when you have a lot compared to other people although I do agree that when you have been through a shit time, comparing your new improved life can cheer you up.
Sometimes no amount of looking at all the good things you've got and thinking you should be grateful makes you feel happy. Eg if you have depression, or if you are just bored, or if you feel unwanted and unimportant. Somebody mentioned unresolved childhood issues and I agree, if you have them, and they are unresolved, even if it looks on paper that you have the perfect life, you won't be happy (this was me).
It sounds like as this thread has progressed you are starting to pinpoint the main cause of your discontent as your DH not making you feel important and wanted.
I think this is really common in long relationships after a while. So is men staring at the TV when you are talking to them and men not taking the initiative to organise nights out. Hopefully you can get some comfort from knowing other people's DHs are similar.
I don't think booking a time to talk about serious issues is the best idea. This is just scary for a man. Men hate talking about emotional issues especially when they are being criticised and booking a time is like backing him into a corner and forcing him to take it.
I think you need to find more subtle ways to talk to him which he finds less threatening. Have you read Men are from Mars, Women are from Venus, or Why men don't listen and women can't read maps, or Surrendered Wife? I know feminists HATE these books, but just try it and see if it sounds like you and your DH. I felt relieved when I read them. It's not because he doesn't love you it is because men's brains are wired differently to women's.
You could then read out bits to your DH and have a lighthearted conversation about "You do this and I feel just like these women are saying...." and "How do you feel when I ....in the book it says....". I did this with my DH and we often talk about what men want and what women want and how to understand each other. We are now starting to understand each other more and do a bit more of what each other wants.