I have constant thoughts that i have become a kafir or have committed shirk. Please tell me if this is shirk. After namaz i was making dua to Allah (subhana wa ta’la) and some light was coming through the window so when i closed my eyes i could see a little brightness. For a moment i had strange thoughts come into my mind like the light or from Allah (subhana wa ta’la). Now i think i committed shirk.
My second question is that if i committed shirk before or kufr, I have to take the shahada again. Is it neccessary to do ghusl as well or will sayaing the shahada suffice. Jazak Allah.