Do i have Lymphoma

Hi, i am an athletic 15 year old male. About 9 months ago, I noticed a swollen lymph node on the back of my neck, when i felt it it was tender, warm, and hurt when i touched it. But now 9 months later i still have that same swollen lymph node, which is about 1 cm in diameter, its hard, painless, and fixed in one spot. When i first got this swollen lymph node i was alway squeezing it pressing it and i don't if that is the cause for it being the way it is now. The same thing happened again on a different area except it feels like two swollen lymph are stuck together. I also get swollen lymph nodes on my armpits,which are always tender, warm and hurt to touch, but go away fully after 1 week. I am really worried that i have cancer.

Any feedback would be appreciated.

Thank you and God bless!