I am constantly bloated and look like I'm pregnant, what's wrong with me?

Recently I have been bloated and yucky feeling constantly. It gets worse when I eat anything, and it never fully goes away even when I go to sleep. I think I might have an allergy to something to something or a problem with my intestins. I look and feel away all the time, and it's really taking a tole on my self estime because I look fat. I need help please!