Depression and Anxiety can often lead to spiral logic. This is when the having depression or anxiety is enough to make your depression or anxiety worse. It does not take much, just one bad moment or day. Just enough for your mind to feed on. Soon you are depressed because you are depressed, you are stressed because your are stressed and you are having an anxiety attack because you felt anxious.
Your mental health is a gross eater. It feeds on itself growing worse and worse on its own power. You fight so hard, but one misstep no matter how small hurts. Your mind finds that wound and tears it wider and wider as you dwell on it. Every step backwards can feel like a fall off a cliff back to where you started, but perhaps each climb back up gets a little more easy.