Terrible problem when smoking marijuana !!

Hello ppl,
I am having some stomach inflamation problem I must eat on time or I get very sick.
the problem is that this thing is not normal , like any other sickman has.
When i`m sick i feel like dying.....i have no pain at all only this strange feeling..at first i thot it's my heart but i went to doctor and he said stomach problem.
The problem is getting worse when i smoke marijuana.after i take 3-4 hits from a joint i must "concentrate to stay alive", my stomach have impressive acid and i feel like my body is going crazy ( iregular heart beats , etc )
i know other people that have problem with stomach
bigger problem then I do.but they don't have problem with smoking marijuana....
i dunno what can I do to be able to smoke again ?
i do not have this problem when i try extacy.
i have this problem on cocaine also.