Pain in Side

I am having pain in my left side. It has been very bad twice now. It lasted about 30 hours the last time. IF I press undere my rib cage (sideZ with my left hand th epain increases. When I lay down on my back it seems to go away temp. It hurts to ride in a car but get more relief when I stand up or lay down.

Just a minute ago I took some antacid and it came up within 2 minutes. I am having the dry heaves and get temp relief right afterwords. I can't eat anything when this happens.

I have no temp and BP is normal as well as pulse.

I am seeking medical attention soon.     What could this be. ROn