What do you suggest if i may have an sti or sore throat?

Probably no STI: Sore throat is rarely due to STI; it's more likely you just have a cold virus. Gonorrhea is the most common STI that can do this, but most oral gonorrhea causes no symptoms at all. A first oral herpes infection can cause severe sore throat, but usually there are other symptoms as well, i.e. blisters/sores of lips, inside the mouth, etc. In any case, see a doctor if you remain concerned.