I know I'm kind of late to the show here, but I persevere by remembering what I hope for. It can be different for everyone. For me, I have faith that there is more to this life than I can see or feel. And my hope is in the promise that I will be restored in the afterlife. For others, it can be hope for things to be better in this life in their future. Regardless though, it's ok to be depressed and allow yourself time to grieve about things but it is important to set yourself limits on how long you are going to do so. Try adding positive things to your life, even if it's in little increments.