Is it worth seeing a doctor again, stomach pain

I have been having pain in my stomach for around 2 years, this is a mixture of extreme stabbing pain (occasionally) and pain while burping (constant, worst at night). other things are feeling bloated after eating, not having much of an appetite, tired and lost weight. I have been to the doctors multiple times first got omeprazole then lansoprazole then ranitidine none of them helped also been tested for H pylori but thats not it, and had my gall bladder scanned with an ultra sound. only thing i havent done yet is have a blood test as im 19 and enjoy going out so im worried what they might find in there. my friends are pretty worried and think i should go back to the doctors but i can kind of handle it, does it sound serious enough that i should go back? and any thoughts on what it could be?