What Causes Bloating Of Abdomen, Fatigue And Shortness Of Breath?

Hi my name is Steve, I am 25 years , male. I have been suffering for the last year and a bit (since i stopped smoking) with the following symptoms : Belching , bloated stomach , fatigue , shortness of breath at times ,bloating makes it hard to breath, symptoms get worse when in moving vehicles. I don t get heartburn or any burning sensation at all in my esophagus. I had a gastroscopy about 3 months a go and was told that i have a Hiatus Hernia. I was put on nexium for a few months...it hasnt helped at all. im convinced that the hiatus hernia has nothing to do with the problem causing my symptoms. I went back to the doctor and was put on treatment for IBS and told to not eat certain foods..... its now 2 months later and i feel like im at the beginning again....feel just as i did the first time i went to the doctor. It is highly frustrating as it is effecting my daily life. Please Please help me understand what is going on.