Mouth problems

Hi , this is the first time i had mouth problems , all started 2 months ago , when i had the first decay , i was moving to another country and didn’t have time to go to a dentist . I checked my mouth every week and had no problem , last time i checked and my mouth and teeth were like before with 1 decay it was 5 days ago .
Yesterday a sensation of a mild pain in my mouth , like between chin and lips but inside my mouth, and in the evening when i checked i had a white spot and it is uncomfortable when i eat and sometimes pain goes to medium to say but usually there is more discomfort than pain . It looks like a canker sore or something similar
Yesterday i also felt my teeth were weak and a sensation of dizziness on them , today in the morning
when i checked my mouth , the white spot was a little bit smaller , it wasn’t big sized before , it remains still uncomfortable to move my jaw or to eat , after i checked my teeth , i had 7 decays , some with 1 black spot on them and few with 2 or more black spots , they are in a normal shape only with black spots on them , i feel like my lips got a feeling of inflated and when i open my mouth completely it feels very uncomfortable . I also
got a dry neck on the upper part of it , the bottom part of my neck feels normal , the upper part gets dry even after i drink water and it feels inflated , when i breath with my mouth i breath a little bit harder than usually , and it feels like i have something in my upper part on neck and even in mouth . 1 time my pus got out my sinus and went straight to my throat and i have the same sensation but that time my mouth smelled for few days and felt head dizziness, right now my mouth doesn’t have a bad smelling but it feels weak especially my teeth , and my respiration feels not normal it feels warmer than usually i feel like when i was in hospital few months ago and there were many people with fever , the air is the same but i don’t feel i breath it , i feel inside my mouth and neck , i think i have an infection , but i’m hopping not to have some neck or mouth big problems. when i was in hospital i was diagnosed with allergic edema , acute urticaria and reactive arthritis, recently i also felt a joint pain on my left hand but it was for a short time . And before that i was sick , i felt my immunity system was weak . I said all of these maybe they are related to what i am having right now

if you need any more informations i am gonna write here , or if you need a photo or something , but literary i feel that my mouth is infected and it feels so bad and uncomfortable and i have also a sensation on my teeth when i put my tongue on them , a sensation like they are dirty but i brushed my teeth twice a day in last months , only a pause when i was on the way to that new country , like 2 days , and i was thinking if it is like a problem with nerves but i don’t know for sure