GI system tore up after FOLFIRI

I'm 3 years out since Neoadjuvant FLOT followed by esophagastrectomy. Multiple advancements of stage 4 and have been through multiple chemo cocktails and immunotherapy regimens. I just had my first dose of FOFIRI and didn't tolerate this well at all. On the fence about discontinuing therapy and going strictly palliative. The FOLFIRI is meant to be palliative as opposed to curative and I have multiple (well over 20 sites) tumors in thorax and a few in the abdomen (one oblated with radiation as it was pushing on some spinal nerves). Since my first dose of FOLFIRI, my GI system has been tore up. Pain after I eat anything. I'm 10 days out from the first dose and all other symptoms have resolved except the abdominal (intestinal) pain. I find the only thing that has been working is the narcotics, but it sucks that I would need t surrender to narcotics now. I guess the question is, how well is FOLFIRI tolerated and what besides narcotics eases that intestinal pain, cramping, burning? I really don't think that I can tolerate this treatment every 2 weeks. Health care team did a scan which showed a little diverticulosis without diverticulitis and did not attribute this to the pain. H2 blocker, Tums and narcotics to treat.