I am getting Wasawis, how do i control my thoughts?

Assalamu Alaikum. Please help me.

My mind is weak, emotionally. Im good in subjects like math, computations, and the like but I am very bad in managing my emotions and controlling my thoughts. I am a practicing Muslim, Alhamdulillah, and gone are the days of me indulging myself in sins and disobedience to Allah, In shaa Allah. Back then, every time I intend and do worship Allah like in Tahajjud, I get very severe waswas that speaks bad thoughts about Islam, the Qur’an and sometimes Allah and I’ve been searching countless of times about these and found out these are waswas. Alhamdulillah, after this Ramadan they went away but not totally. I gave up pornography (this was my addiction then but In sha Allah, with conviction, I wont go back to this shameful act) , music, and watching TV shows that may not help me to be a good person and a Muslim. Recently, I experienced the sweetness of faith by praying 5 times a day and pondering over the meaning of Qur’an and the beauty of Islam and it affected me outwardly because I appreciate my parents and love them even more. I even said, such a very beautiful blessing Islam is, and whenever I read Qur’an, I always say this is with no doubt, a miracle of Allah for these words are indeed His words. Recently, the waswas are coming back bit by bit but this is different than before, these are whispering Kufr. It’s like these waswas are saying that I am not a Muslim because I did this and did that. Out of fear, I always say Shahada and Lailaha Illalah whenever I sleep and declare that I will live as a Muslim and die as a Muslim In shaa Allah. Now, another problem arise, the waswas are telling me that I am having doubts about my faith and these leave me very confused. When I make dua’a, these thoughts are so severe that they even question the existence of the Creator, Astaghfirullah. At first, I dismissed these thoughts, but as I said, my mind is weak, I am on the assumption that I really thought about these and these were not waswas. I am in great distress as I don’t want to live as  a Muslim WITH A DOUBT in his heart, I want to be a SINCERE Muslim and I am so scared that I may die while having these. I always pray to Allah that if this is indeed a test, then I will bear it with patience and I am doing my best to dismiss that disturbing question about His existence and I always rub my chest and I always say that I believe in Allah and He is the Creator of All Things. Now there’s a problem, I sometimes think that I am not sincere towards these, I get lots of what ifs what ifs ideas. I am really in distress. Please help me regarding my situation.