In my view…

Joy is not a feeling in the common interpretation of the word.

Joy is a state of being.

Joy is expansive – it is large enough for all emotional states to be present within it.

Anger is not the opposite of Joy.

Joy is not achieved through banishing Anger or grasping for a more desirable emotional state.

Joy is big enough to include and be with all of Anger.

Ditto – sadness, despair, elation, doubt etc…

Joy exists in the choice to not reject any of it, to allow and honour all of it.

Some possible access points:

And don’t forget breathing deeply and allowing yourself to be a blissfully misunderstood infinitely deep confused slightly crazy grotesquely flawed human being. In fact – I think that bit is essential.