Pain Left Bottom Ribs After I Have Eaten. Not Always

Pain left bottom ribs after I have eaten. Not always but gets more pronounced. Also After I have sat down. Also tinkling and muscle pains all over the torso at times, worse when it is cold. Muscles feel tender. Do have existing lower back problems but now also between shoulder blades. Sometimes a bit pain in liver area. Also developed rash at bottom of skull which I have had before but then disappeared. Had some mouth sores last week but mostly gone now.
Earlier in the year I was in southern africa and had a few strange bites , but nothing that worried me. I am now in Hawaii for a few weeks.i am female, 68 yrs, 176 cm and 72 kg