So many times I've gone into depression, still struggling & hoping, reciting quran, offering different prayers but its human nature to think where are my duas going? Why aren't they answered?

I can fully understand your frustration but the biggest solace for you me and anyone who pray and do duas and their prayers and duas do not give fruition is to remember that Imam Hussain also prayed on Ashura day to save his Ali Akbar, Ali Asghar, Abbas but non of that happened !!! But did the imam say why? No why? Because he knows that Allah knows best and we should keep praying if our prayers are not answered now they will definitely be answered later or on the day of judgment. Don’t give up on hope.