Assalamu Alaikum
I am 15 year old boy who has found the path and guidance of Allah SWT, The exalted, most gracious, most merciful. I have been trying my best to stay away from anything considered haram noted in hadiths and the noble Quran; however recently while recalling some of my past behaviours ranging from 2-3 years ago, I remember in multiple fits of rage I insulted and reviled Allah SWT. I am currently in deep regret and despair, as some point out that in doing this throws you out the folds of islam, and Im scared that Allah SWT will never forgive me for this, as in doing this for puts me as an apostate of islam. I have already repeated my shahada on multiple accounts, performed ghusl, and prayed salat-al-tawbah in sincere repentance. Is this Kufr, and will this be forgiven. Astagfurallah.
Allah knows best.