I'd like to send some gentle hugs your way...

Losing 120 pounds is such an achievement! Everyone has ups and downs as far as weight. You've noticed that you've gained 20 pounds back. You caught it early. What is 20 pounds compared to 120 pounds? It will come off before you know it and you'll be back to normal. You've caught it and can be more careful from now on. It's not too late! You haven't undone all your progress, even if it feels that way! Promise!