Hi I Have Had Ongoing Pains Aroung My Left Rib

Hi I have had ongoing pains aroung my left rib cage. Sometimes it feels like something is stuck under my left ribcage, and when I lie on my left side it feels like there is a mass under there which feels like it is pressing against my skin. Sometimes the pain is in the left of my back above waist level. At the moment there is huge tenderness which feels like a terrible bruise when i press at the front on the bend where the ribcage starts to slope away to the left, while the niggly back pain is almost always there.
I have an angiomyolipoa on my left kidney, which I have been assured should give me no pain. My GP has sent me for an MRI scan which revealed nothing.
There are stomach problems in my family. My mum has a hiatal hernia, and says the symtoms are similar to hers. I can burp at will, but have no acid reflux feeling.
My GP gave me NSAID with OMEPRAZOLE which made a big difference for a month. After that he said he thought it was postural, and if it returned I should go back to see him.
I am going through a very stressful time at the moent as my ex husband has just died at the age of 47 from colorectal cancer. The stress of looking after him and worrying about my kids and planning his funeral seem to have sent the symptoms into overdrive.
Can you shed any light on this please?