Sadness in the C line

Dear Brooke, I’ve been doing this work for so long and I can’t stop feeling sad. I wish it was 50:50 but I have struggled to create joy in my life.It’s been this way as long as I can remember. I’m totally functional but mostly unhappy. I know that the solution is not ‘out there’ – I’m slim, don’t drink, healthy, have had a successful career, have a nice home, beautiful children and stable family. I’ve had ups and downs in life but nothing I’d consider a huge trauma. I’ve tried different jobs, cities, relationships etc and I feel basically the same.
I don’t want to be sad. I don’t feel like I’m choosing it. I keep working on the thoughts that create the feeling of sadness (mostly things like ‘I’m lonely’ ‘I haven’t accomplished enough’) but it feels as though I’m looking for reasons that aren’t really there and that I’m mostly sad because I feel badly and feel worse when I’m trying to change and failing. The model I have today is
T I’m afraid I’m going to ‘fail’ SCS – so many people have got amazing results, I’m not making it work and I can’t figure out why. It’s my fault.
F Despair, failure, powerless
A Cry. Withdraw.
R Shame – feel worse = failing

If I put sadness into the C line as a sensation, it serves me. I can create thoughts like “I can feel sad but still get work done” and “I can feel sad but still be loving towards my children” that enable me to keep going. But I’m not solving the root problem. Is there something I can do differently?