Salamo alaikum sister,
it is quite healthy to go through these thoughts as they are a sign of strong eeman.
Hazrat Umar R.A, the beloved companion of the Prophet Muhammad saww, was also a revert, but before reverting he was a strong enemy of muslims, but after reverting to Islam he used to cry so much over his earlier ways, even though he had been given many blessings from Allah swt. It is his famous quote that,
" Were all the good people from this world to be lifted into jannah, and Allah swt announced that there is only person who will go to hell fire, I would think that it is definitely me."
And we all know that he had such a strong faith, that The Prophet Muhammad saww had once praised him by saying " Were there a Prophet after me, it would be Umar r.a." And Umar R.A was among the only 10 people who had been given the news in their life times that they will go to jannah, such was the level of service they had for islam, and such was their state of worry that Allah swt foretold them so that they would worry less. And such was their gratitude, that those companions started working even more in the way of Allah swt, in order to be worthy of such a blessing.
It is also said in a hadith, that Even Shaitan was so scared of Hazrat Umar that he used to change his way if he saw Umar R.A coming ahead. (because shaitan probably knew that if he cast a doubt to Umar r.a, Umar would become more strong in his faith)
Hence, we should also adopt the same approach and try to become more strong by reading the Quran, listening/attending to its scholarly explanation, because that really makes you faith really strong, Alhamdulilah, and cures away all those doubts.