Brother, salam wa rahmatullah wa barakatuhu
my advice is remember Allah often, study Islam more8the miracles, the prophecies the Quran, the Hadith) and answer that atheist guy, not by debating or stuff(it's useless trust me<experience) but by letting him know with a big and sincere smile that Islam is the best thing that ever happened to you and nothing (In sha Allah) wil make you think the countrary, tell him that his continuous talk is boring if that's all he has to say he should stop, tell him that you fell in love with the peace that the prayer gives you, and the awe that the Quran inspires you and the aspirations that our model (Rasulullah) inspire you...and lastly but most importantly: talk to Allah!
If you don't talk to Him, and don't tell Him that you're in difficulty how can He help you?..but still i want to believe that this answer of mine in sha Allah is part of Allah's grace on you so return to Allah literally and trust yourself to Him and you'll succeed in this life and the akhira in sha Allah
wa salam