I think it is impossible to be filled with joy in the faith. I think it is only possible to be filled with joy in G-d.
I don't know what other religions you have studied. I have studied many, and I know of no other that offer a relationship with their god. Many don't offer even the ability to communicate with their god. Some offer the ability to appease their god when life is going badly, but there are no guarantees. Maybe you are aware of some that I am not aware of.
But if they all look equally valid to you, the I will offer you one other place to look. You will have to travel far to find it and you may not be sure you have found it when you get there.
It's a tomb that was full but is now empty.
Shalom.
You including Judaism in that?
It's not exactly mainstream Judaism, but I feel/yearn for a relationship with God, like that He had with Abraham and Jacob: Argumentative, questioning, occasionally exasperating to both sides -- but a relationship between two rational beings, one the teacher, the other -- not really a student, but a learner.
I certainly don't have with the strength that Abraham had. But I feel that I'm on the right track for me.