Benjammin:
I have asked the same question as you, “does God really want us to be happy,” many times, as I have struggled with bipolar disorder and depression for most of my life (I’m now 42).
I don’t believe that God created us to be happy any more than he created us to be sad or angry. However, unhappiness and hardship in life are actually opportunities that can grant us the gifts of the Holy Spirit: Wisdom, Understanding, Counsel, Fortitude, Knowledge, Piety, and Fear of the Lord. As these are the same gifts that came with confirmation, I often pray to my confirmation saint in difficult times.
Also, if you reflect upon the lives of the saints and martyrs, those who are most favored by God, they had a lot of adversity–more so than the “average” person-- but they also had great blessings because they did not lose their faith. It took me a long time to realize this, but suffering and hardship in life may actually be gifts, because they can bring you closer to God, help you to gain grace and other gifts, and help you to be more empathetic and caring of fellow human beings and even animals in hardships, which puts you in a better position to love and help your neighbor and do God’s will.
Here is what I have come to believe. I believe that happiness is an emotion like any other, and as such, it is only a temporary state of feeling and being. Emotions are fleeting, but we can gain something spiritually from even negative situations and negative emotions. That is because God’s love is perfect, lasting, and unconditional. We have the free will to choose much in our life, but we must have faith in order to see hardship and unhappiness as gifts, so I often also pray for increased faith in difficult times. I think that God wants us to be content in our lives and secure in his love. I hope this helps.