I need Motivation

Hey everyone... so honestly I just need motivation. I recently found out that I’ve gained some significant amount of weight, and I can tell because a dress I bought a while ago does not fit me well anymore. To be honest, i shouldn’t be so surprised because I had not been working out much, but I thought I was eating healthy. Guess I wasn’t :/

Now I kinda just feel like giving up and letting my self go and I just feel so down by these news. But another part of me feels like going crazy and working out like a maniac.

What do you do to get back on track? And what do you recommend I do? Also, what do you think will help me shed some weight pretty quickly?

Any tips or anything at all is very welcome and I will be very thankful for it.