I'm sorry that you're feeling like this.

Maybe you need to consider reconnecting with your therapist or even review going back on some kind of medication for awhile. I know it feels bad to seem like you're going backwards. But it's almost certainly for the best to try and get on top of this now, in case it gets much worse and harder. Consider it maintenance.

Even if it is transient, would it really be so bad to stomp that depression to the curb to keep it from potentially growing so big again? You did it before, from the sounds of it, you can do it again.