There is a joy that grows only in the fertile ground of pain and suffering. I think that's what Jesus called "my joy." It's abundant and overflowing joy. It cannot be contained--not even by pain. It's not relegated to happy circumstances. Jesus spoke of having our joy made full and complete. It makes sense that if we experience His joy, it would overflow from our hurting hearts.
Have I got that joy? It doesn't always FEEL like it. Rather, what I often feel is the weight of nearly 15 years of walking through relentless trauma between a son out-of-control on drugs, capping it off with the diagnosis and death of my late husband from a brain tumor. If I let them, my feelings can be all consuming and drown out any hope of joy in my life. However, I am not the only one who has found herself overcome by pain and suffering, but still found joy. Paul found joy in the midst of conflict and rejection left to rot in a jail cell. Jesus had it, as well, as He faced the cross (Hebrews 12:2).
To be honest, I'm not always feeling the joy. I'm still seeking, groping my way in the dark looking for it. Intellectually, I know that joy is Jesus Himself, a Fruit of the Spirit, the evidence of God's Life and He's in me. The Scriptures say in James 1:2, "Consider it all joy, my brothers and sisters, whenever you encounter various trials," This verse, by itself, is a problem, because you're left to believe that the pain and suffering produced by trials is fun. Oh, boy!! But it's the next two verses that give meaning to the first. "knowing that the testing of your faith produces endurance. And let endurance have its perfect result, so that you may be perfect and complete, lacking in nothing." (James 1:2-3) The point is that we can take joy in the end result of our pain and suffering, which is spiritual maturity.
I don't know about you, but I'm tired of the trials, the pain and suffering, being conformed to Jesus' death, etc., and when I am tired and weary, I seek Jesus and His joy. It seems to be found consciously embracing the mysterious joy in God's heart even when we don't understand and, especially, when we are weary from the journey.