The joy of the Lord is our strength, but there is also a time to grieve and mourn. We are made as emotional beings, so expressing those emotions is appropriate when there is loss or disappointment. That’s why the Holy Spirit is called the Comforter.
Bottling up emotional trauma is a bad idea. You have to find a way to let it out and give it to Jesus. Find a place where you can have a good cry, then hand it to the One who knows your heart better than you do.
There’s no lack of faith in needing to grieve. Even when someone you’ve lost is a believer and you know you’ll see them again in heaven, you’ll still miss them here and that’s ok. Allow the Holy Spirit to give you peace, and then let it go. When you give your grieving to Jesus, He heals the wounds so your memories don’t hurt you. Blessed are those who mourn, for they shall be comforted. (Mat 5:4)
Grief can come in many forms for many reasons, not only when a loved one dies. If a dream you’ve held onto blows up, it’s ok to grieve, but don’t hold on to it any more. God has other plans, better plans.
Take time to mourn when it’s necessary and let the Comforter do His job.