Pain in stomach w/nausea that comes & goes, severe shoulder pain

So I have had this issue with random extreme nausea with severe pain in the upper part of stomach. It's a really weird feeling like I said it's nausea mixed with this really deep pain and it comes on suddenly and it usually only lasts a few minutes but it's very uncomfortable. then I also have this uncomfortable feeling located like under my rib cage on the right side that sometimes feels like something is swollen there..and it's really uncomfortable to move certain ways, like leaning forward. pretty random also, it comes and goes just like the other symptoms but not necessarily all the same time. Also for months now I've had an off and on pain in my shoulders, both shoulders but at different times. right now it's been my left shoulder for a few weeks, it almost feels as if my shoulder is dislocated or something.
it hurts to move it much, especially if I try to put it above my head or reach up or around for something it'll start hurting really bad. but it constantly feels like it's out of place or something. I don't know if all those things have anything to do with one another but all have been going on for many months now & it's really concerning me. I don't have a doctor currently and I really hate to go to the ER unless it's absolutely necessary. FYI if it makes any difference I am autoimmune & have a couple different AI conditions. Psoriasis, UC & not confirmed yet but I assume Psoriatic arthritis.