I have suffered from that in earlier years. Drs. did nothing that helped.
I suffered for hours, sometimes over a whole day before relief came.
I was on a study about this when a boy who was affected died from it. The gas pressure was so great it ruptured his diaphram.
I stumbled on a solution. Pepto Bismol. I took more than the standard dose and in a while I burped a ton of gas. Still had pains for several hours, but if you start the Pepto when you first detect the buildup relief comes within a few minutes. You may need to take a little Pepto for a couple more doses before all symptoms are gone.
I meant to say whole oat cereal and whole wheat BREAD... not whole wheat cereal.
Six years, wow. I think you have constipation. If your bowels are sluggish, the waste stays in there, and thus gas builds up. Also, the toxins from waste have to go somewhere, so you sweat them out, which causes the odor. The symptom that tipped me off is when you said you try to go and cannot. And since it's been going on a long time, constipation can be like that. Some folks are that way for various reasons.
I can give you some tips on how to resolve this, as long as there isn't some underlying disease going on, which your doc or a gastroenterologist can determine if my ideas don't work for you.
First, review all your medications, and if any have the side effect of drying you out, then ask the doc who prescribed those to switch you to something else less drying. Second, many people do not drink enough water, and this can cause dehydration and thus constipation. For the rest of your life, every time you brush your teeth, which should be at least twice a day, drink a few extra glasses of water. Third, if you are sedentary and don't exercise regularly, well you're going to have to do so for you whole life, so at the very least, do some easy stretching exercises until you break a sweat, after which you should drink some more water.
Fourth, on your mission to get your digestion moving more regularly, there are two parts to this. First, whenever you try to go and it won't come out, then you need some medication to get that straight. If the waste is right there but won't budge, then go to the pharmacy and buy the over-the-counter Baby Lax, it's a small box of ointment tubes, squeeze two in there and it'll come out in a few minutes, and repeat as needed. If the waste is further up, you'll need to do some enemas to get it to come loose, you can buy a throw-away bottle already mixed up if you want, might take a few days to get some waste out, so buy a dozen or get a regular enema kit with a bag for water and long tube. Also buy some plain KY jelly for enemas.
Second, once you get your bowels going again, you have to keep them going. This means you have to consume stuff, along with your regular meals, to help your digestion. The main two things to do are add fiber and consume probiotics. Probiotics is simply Acidophilus milk or Activia yogurt, both in the grocery store. Consume those for a couple weeks. The fiber should be the following, and do it forever: Whole oat cereal and whole wheat cereal daily; blueberries and chopped prunes daily on the cereal; a little orange juice, no more than 4oz of any juice daily; spagetti and dark green salad once a week. Also, a half-cup of coffee is great just before you normally go. And remember to continue with good hydration and exercise, along with the fiber.
If this doesn't work, then it means you need to go to the doc. Could be there's a disease that's slowing down your digestion somehow. I really hope these suggestions help you, and I'd like to hear how things go, as I'm sure other visitors to this forum would, too. So, keep us posted.