I am a revert Muslim since November 2016 but before I reverted although I used to believe in Allah (SWT) as one and only true God and in Prophet Muhammad (PBUH) as the last Messanger of Allah (SWT) I was not a practicing Muslim at all and during that time unfortunately I made a huge mistake which today I strongly regret, I am addicted to porn and masturbation and In June 2016 I promissed Allah (SWT) that I would quit watching porn And masturbation and if I would return back to my addiction then he could throw me in the hellfire on the day of judgement even if I worship him in this life and even though I repent to him.
Unfortunately i only lasted 33 days and after that I returned to my addiction and and so unfortunately I broke that promise which I made to Allah (SWT), now I’m truly worried that Allah (SWT) might not forgive me for my foolishness and im worried that he might punish me on the day of judgement even though I became a Muslim and even though I seek his forgiveness, my question is that although I made a huge mistake by making that type of promise, do I have a chance to truly repent to Allah (SWT) knowing that I made that promise in 2016 and is there hope for me despite having made that promise in 2016 which I am truly sorry for now?
There are two separate actions you did:
Made an oath that you would never commit one sin
Prayed that Allah punish you into Hell-fire if you break that oath
Since you broke the oath you need to give the expiation for that.
As far as the dua is concerned, it is not valid. This is based on the following hadith:
"The supplication of a slave continues to be granted as long as he does not supplicate for a sinful thing or for something that would cut off the ties of kinship and he does not grow impatient." It was said: "O Messenger of Allah! What does growing impatient mean?" He (ﷺ) said, "It is one's saying: 'I supplicated again and again but I do not think that my prayer will be answered.' Then he becomes frustrated (in such circumstances) and gives up supplication altogether."
Your dua was obviously sinful, thus it will not be granted. Next time do not make such duas.
Bismillah hir rahman nir raheem As sallamu alaykum wa rahmatullah wa baraktuhu
May allah have mercy on me and you and grant us jannah. You must fast 3 days if you cant you feed 10 poor People. If you need evidences i can send . Never lose hope in mercy of allah but never feel safe from punishment of allah. You must worship Allah upon hope and fear when you sin repent but hope for mecry of allah . Allah knows best as sallamu alaykum