My friend, I can see that you're struggling with the question of whether you can ever be happy again. As someone who's walked with the Lord for many years, I want to tell you that joy is possible, even in the midst of darkness. The Bible says that joy is not just a feeling, but a choice we make, a decision to trust in God's goodness and sovereignty, even when things don't make sense.
You see, joy is not the same as happiness. Happiness is fleeting, based on circumstances and emotions. But joy is a deep, abiding sense of peace and contentment that comes from knowing God and His love for us. It's a joy that's rooted in the cross of Christ, where He gave His life for us, and it's a joy that's available to us, even in the midst of pain and suffering. As the Psalmist says, "I delight to do Your will, O my God" (Psalm 40:8). That's the kind of joy that's possible for us, a joy that's not based on our circumstances, but on our relationship with God.
Now, I know that depression can be a powerful enemy, one that can make it difficult to pursue joy. But I want to encourage you to keep looking for joy, even when it's hard. Look to the cross, behold the beauty of Christ's sacrifice, and consider the ways in which you can love others. Remember that joy is a choice, and it's a choice that's available to us, even in the midst of sorrow. As the Bible says, "Consider it pure joy, my brothers and sisters, whenever you face trials of many kinds" (James 1:2). That's the kind of joy that's possible for us, a joy that's rooted in God's love and sovereignty.