My personal thoughts are 1) DON'T TAKE THIS PERSONALLY!! You are stressing too much over the crate issue which is why your stomach is in knots. Have your tried an x-pen? Sometimes it also makes a difference, as Jennifer stated, between a wire crate and a plastic crate. You will need to crate train him for the car, or if you go away, however, so I would keep trying with the crate.
Back to square one. Feed him in the crate. Start with the door open and then slowly adjust it so the door is closed, then locked. Then, after eating, or while he is in the middle of eating, take him outside for a potty break and put him back in for a couple of minutes. I have one girl who will scream, throw herself, do a Linda Blair exorcist routine, poop, throw it, etc while crated in my house. However, in the car, or in a hotel room, she is not bad. In the hotel room, when I leave she settles down and is quiet. Most dogs, in my experience, will settle down after 10-15 min of you being gone and are quiet, then, when they hear you, they start back up again. So you may think they are screaming the whole time, when they are actually not.
Sometimes toys, foods work, sometimes they don't. I had to ride it out with my youngest boy. He's a year now and he's just settling into a crate routine. If I say crate, he will go in and be quiet, but it took about a year.
There are no magic bullets. Some people are also great at crate training, some people are not so good. I'm not the greatest, but persistence is my key. Also, take him for rides in the car, in the crate. IMO this helps also.