Giacomo-
Forgive me for being cliche, but life is about balance. In this case a balance of your environment, interactions and responses to situations. Guilt is taught to some of us as a young age- the “suffer more to be a better person” complex. Perhaps try returning to something that gave you joy in the past? Art or music or the outdoors. Try to find time (even an hour) a week to return to that happiness.
Sunlight WILL boost mood. As will finding things that make you remember good times. Oh, and hug anyone you feel good hugging. Always helps me.
I am new to the site myself and am less eloquent than many here, but I hope something of my suggestions help you.
Cordially-
Feaiths