Im 16 Years Old...do I Have Lymphoma ?!?!? Urgent?

well like 3 to 4 weeks agoo my right back gums became very swollen and on that same side my lymph node became big and was painful to the point it was hard to swallow & turn my head...so after awhile i rinsed with salt water and a few days later my gum swelling went down(but was still swollen) and the lymph node pain went away...THen i went to the dentist && he said my gums were inflammed and told me to continue to rinse with warm salt water, currently im doing that because my gums are still swollen && my lymph node hasnt reduced in size...the lymph node is tender and movible &&when i say movible i mean i can move it to this one location in my neck and make it dissappear but if i move my neck again it'll come back... MY mom wont take me to the doctor because she said im jus overreacting.. But im worried...Is this lymphoma cus my lymph node is about the size of a penny but a bit smaller && movible as you already kno..i dont smoke or anything &&im a athlete..plus i currently have a cold if that helps ..but i really dont wanna die ...can you give me straight Accurate answers....Thanks a lot.
lymphoma is very much life threatening ..&& im not overreacting because no lymph node should be swollen for this long.