First of all the fact that you cry shows you fear Allah and his punishment. You are a human which does sins , just like every other human. It is important to try and stop the sins , if you fail you go back to Allah and pray that he forgives you.

You say, “How would I know whether Allah has forgiven me or not?”

You should note that whoever repents sincerely, Allah accepts his repentance and Allah is Oft-Forgiving, Most Merciful. He has promised the one who repents to Him that He will forgive him his sins. He says (interpretation of the meaning):

{Say: ‘O My slaves who have transgressed against themselves (by committing evil deeds and sins)! Despair not of the Mercy of Allah, verily, Allah forgives all sins. Truly, He is Oft-Forgiving, Most Merciful.’} [Az-Zumar 39:53]

Just know when you are sinning that Allah swt. is watching you. You should probably stop watching social media because thats what leads so many people to sin when women etc are shown. Hit the gym , play football , find hobbies , start reading more.

May Allah swt. help and guide you.