Lump under armpit!

Hey guys I’ve been extremely concerned over a lump in my armpit, it’s extremely swollen and visually bigger than my other armpit and it’s causing me a lot of pain. 

I’m 14 and I’ve had this lump for over a year, I wasn’t going to mention it until I saw a sign left up on a wall saying that lumps under armpits can be breast cancer which scared me into telling my parents. 

They got me into private healthcare and we went to see a consultant, he felt where the lump is and said that he couldn’t feel anything, but this confused me as I can feel a lump very clearly, and before I went private healthcare I went to the local doctors and they said they can feel an olive sized lump as well. My consultant said it is most likely hormonal and nothing to worry about, but he got me to do an ultrasound just to be safe, and nothing showed up on there either, the only thing I was told to do was to come back if it gets any bigger. I’m just really concerned about it and I really don’t think it’s normal to develop a lump just because i’m hormonal, it’s extremely painful, especially when touched, it’s a stinging pain like rubbing salt into a cut. I’ve also noticed it hurts significantly more when i’m sweating/ moving my arm about, I have no idea what it is and i’m not sure it is cancer, but I just need somebody to talk to as nobody seems to be taking me seriously.