Honestly Iโve never felt happy to start with.
I have family members who have struggled with anger and depression. In my limited sample, the ones who have never been happy have had chemical imbalances, and most of the issues went away when their chemical systems were managed. If you haven't spoken with a doctor about it, you should really consider it. There isn't a lot to lose, and there's an awful lot to gain.
Whatever you decide, good luck and I hope you can find some inner peace.