I have had this problem several times. Its been a particularly rough year for me this year. about
a month ago, I finally got out of the hospital after spending 360 days there just to get diagnosed with UC a couple of weeks later. At times I felt like everytime something would get better, something else would happen, but I learned several things over this past year that help me find joy when there seems to be none.....
1) My faith is the key to my joy. I by all medical explanations should not still be here (and yes some days I feel so bad that I wonder if that is a good thing), but God has a purpose for me here and according to Him, He wants us to have life and have it more abundantly. So I search how I can do that. I find things I still can do that bring me happiness and joy.
2) God is the healer and will work in His timing. I just have to be patient (easier said than done lol)
3)Praise, praise, praise.....even when things are awful, praise. It lifts your spirits.
4) In those loneliest, darkest hours, I remember I am not alone in this.
I know not everyone believes, and I respect that. But for me, this is the only things that gets me through sometimes.
Volunteering is a great idea too.
Hope this helps!