Great difficulty eating and with bowel movement

I have had issues with my stomach for the past 10 years.
I was always a healthy person who loved exercising. Then in Summer of 1997 at the age of 24 I noticed a slight discomfort in my stomach when I exercised. I would feel very bloated to the point of wanting to throw up. About a month after I first noticed this happening I was no longer able to exercise. Anytime I would try to just run, I would start to dry heave.
After seeing my doctor I was send to a specialist. The specialist had me on H Pylori program. This didn't help.
I was then told that my gull bladder needed to be taken out. It was taken out however it did not help any.
I have had a camera into my stomach a few times in the past few years however nothing was ever found. After 2 years of seeing my GI specialist I was told there was nothing he could do and was send back to my regular doctor.

Here's some symptoms I experience on daily bases.

After eating [ even small amounts] I feel very full and bloated. My stomach feels very tense and closed.I have to take a deep breath and release a deep burp in order to feel a little better. If I am not able to burp I will usually end up throwing up the food I just consumed.
It doesn't matter what type of food I consume. I have changed my diet a number of times over the last few years to see if anything will help.

I have had a real issue with bowel movement. This wasn't always a problem. It started about 5 years ago. I now consume natural Senna tablets every night to help with this[as per my doctor's instructions]. My stool is very soft and full of mucus. All the time.

Smoking and drinking definitely worsens my condition.
The morning after drinking my stomach feels like it's shut closed. Again I need to release a burp to ease the tension in my stomach however I can not do this. I usually end up dry heaving the whole day. [Needless to say I have quit drinking]

Any help or suggestions is greatly appreciated