Normal lymph nodes or potentially serious?

[Tooyoungandafraid]

I just turned 15 last month,and i've had this swollen lymph nodes since last week, the first time i got it,it wasn't painful unless i touch it and was just on one spot,i told my mum and went to the doctor with her,the doctor said it was just normal lymph node and there wasn't really any problem with it, she prescripted dexamethasone 0.5 mg and cefadroxil 500 mg,my mother refused to buy the medicine right away and insisted i take herbal medication instead,such as drinking warm ginger water,cleaning my mouth with mouth washer,and eating/drinking some kind of medical leaf that can cure throat inflammation or some sort(not really sure what the leaf is called),on the second week though,i started to have a fever, and felt  very weak too and  then i started to have a bad diarrhea,the poop was liquid watery,i told her to buy the medicine because i thought it was getting worse,she bought it 1 or 2 days later i think,i've been drinking the medicine for 2 days straight now and still feel weak my mum told me to eat honey and vitamin c but there's literally no difference,maybe slightly but i still felt incredbly weak,i also drank something called enercore with 5000 mg d-ribose,it was something like that,it helped me before and i felt quite better,but now i don't even feel any difference after drinking it, last night i started to have diarrhea again even though it was getting better for some time,i barely even eat anything that can cause it,it was hard for me to sleep too, i woke up like an hour after i slept,didn't feel sleepy at all and my stomach felt incredibly uncomfortable,i farted quite alot too, perhaps more than 20times,i finally was able to sleep at around 3 am, today though, i had a very high fever and can barely stand up and walk each time i walk i felt like i was about to fall or faint, i decided to eat some cookies(i lost my appetite i only ate 2 pieces of bread before eating my medicine) and i also decided to take a bath because i didnt take any the other day,i felt better soon enough for about less tham an hour and started to feel very weak again,literally my whole body feels uncomfortablr now,i had some muscle aches when i woke up too,i think the lymph nodes around my throst id  starting to increase too(i'm not sure) and the first lymph node that i had since the other week doesnt even hurt when i touch it now. Can anyone give me an answer whether this might be serious or not,please? thanks(sorry for my bad english)