How can I help my loved one keep calm during breakthrough pain?

My heart breaks for him.

The love of my life has stage 4 non-small cell Lung cancer. Initially stage 2 and on my 57th birthday I was told after VATS attempt was unsuccessful because two 1mm nodules were found on pleural wall. (Removed and biopsied), lung was not resectable. But now Inoperable and at that point stage 4... stage 4??? No lymph nodes. Still contained within the pleural wall. No Mets. Only lower left involvement. I understand quite a bit of the medical side of this from reading and I have also seen him through open heart valve replacement surgery in 2015.. He is 330 lbs. Copd, sleep apnea, diabetes, PAD, deaf, gout. He has more life and love than any man I know.❤ Him, not so much.

I try to explain. I track all his symptoms and do my best but I feel I am failing him. I take control of speaking to doctors. I have found too many times I have not been listened to by doctors. Even to the point his life has been jeopardized. I have no formal medical education. But I am literate. The most recent was what sounded to me like a pleural effusion. I was told no. I accepted that... But he ended up in the er with shortness of breath in late June. CT clearly reported small Pleural Effusion. Since he went in with a bad case of diarhea and he was on a 2nd cycle of tecentric. They diagnosed immunotherapy related colitis. I explained that his metformin dosage had also been doubled within the last few weeks and his bowel issue was suspected at a colonoscopy 8 months prior to either of those situations. He even had a peri-anal abcess treated 6 months earlier Just prior to that He was being set up for cyberknife Again all prior to tecentric treatment which was started in April. and at the planning CT several pulmonary embolism were found in both lungs.

He was prescribed 150 mg injections of lovenox 2's daily. Home injections morning and night. He has started a new chemo in June Taxatere along with 10 straight days of standard radiation. Now the aortic arch has an annyurism.

We will see cardiac surgeon on Wednesday.. during the time of VATS surgery 6th rib was broken now 11th rib is broken. Again I believed his symptoms seemed consistent with what I read on all reports stating pleural effusion. I was actually bluntly told no not a worry. When the radiation was over I could not stand the obvious decline in his health and upon demand went to ER. He had a thorarocrntis where 1200 'll were drained from effusion. He is slow coming back... I am frustrated. Any advice??