Belching, hiccups, farting, nausea, vomiting and some chest and back pain what could this be? (chronic) omeprazole doesn't help, no blood problems.

See a GI doc. At this point certainly i would like you to follow up with a GI doc. There are other medications like Omeprazole that may help. Also there may be further lab testing or endoscopy that may be necessary. Good luck.