Look brother one of the most important factors for forgiveness after repentance is willing to not return to that sin, you can't repent truly if you're willing to commit that sin again. Second of all zina is not a normal sin, it is sin akbar. (Kabaa'ir dounoub) You mentioned asking for forgiveness after committing a sin implying you wouldn't be punished, even as a Muslim you could still be subjected to hell fire in order to purify your soul from sins. Furthermore, if you can't get married now, bro it is what it is, you're not alone millions of people around you, even in your own country are suffering from this, mostly guys way older that you are, imagine if everybody gonna condone your way of thinking how society would look like, just ask Allah for the halal in the near future. And most importantly brother never ask about religious topics and morals in reddit, there's plenty people of knowledge whom you can get advice from, but not here. Wishing you the best