Hi , I'm 17 and have underactive thyroid and I have had it for 4 years , recently I've started to notice that I have swollen glands that have been there for a couple of months and I have a pea sized lump under my chin that has been there for a month , I was given antibiotics to see if it would go away but they didn't do anything , today I started to feel pain in my breast and armpit and discovered a hard lump that you can't see but can feel above my breast but under my collar bone on my left side , I have been getting really tired and sleeping a lot , I also haven't been hungry and missing meals , any idea of what this could be ? Thankyou