Suggest Medication For Pain On The Right Side

Hello, I haven't had any trauma to my ribs or anything that I can possibly think of that could have caused this - and I am 34 years old, healthy, eat well - but about four/five weeks ago I started to notice some pain in my right side, in one specific place. I found it difficult to sleep on that side. I also noticed a swelling, which now, when I prod around it (I am taking painkillers and muscle relaxant which helps the pain), seems to be a smoothish bony lump rising from the rib itself almost at an angle. It's located on I think the 8th rib on my side, about 5-10 cm down from where my bra lies. I haven't been able to get an x-ray yet, but I'm already panicking about what it could be, since I cannot think of anything that could have caused this!