Why do my white spots on my tonsils keep coming back?

I have had white spots on my tonsils for at least 2-3 months (not tonsil stones that can fall out or be removed) without stopping... sometimes a big pain comes when I swallow especially those like 2-3 day passes it hurts 1 week I'm ok 2-3 day I'm very sore Ect... it never goes away completely my girlfriend has exactly the same thing she did the strep test negative and the mononucleosis negative too so I'm thinking that it's not its contagious... I had seen a doctor in zoom 28 June who thought maybe a strep so he gave me Penicillin Amox 2 times a day for 10 days, it took away my sore throat on the spot and made me not feel "sick" anymore but the stain remains and it always comes back the little sore throat .... not to mention the funny taste in my mouth! I brush my teeth 2 times a day WITHOUT EXCEPTION, dental care, mouthwash etc. so it's not that either the air in my room ? with the fan h24 + air conditioning it always happens in summer my sore throat weird Would you have an idea of what it could be? What should I do? I just turned 18 so I'm currently waiting for my family doctor so it's not easy to get an appointment unfortunately that's why I had seen a doctor on OLIVE. I'm a little paranoid too and I'm worried that it could be something serious like throat cancer or something like that! (I don't smoke, I don't drink)