If you want to lose weight, it's not enough to just exercise. At the very least you need to write down everything you eat or drink.
Ideally, you'd use an app to calculate your caloric intake vs burn. I like My Fitness Pal. It's free, easy to use, has a huge data base of foods, and is easy and intuitive to connect it to the Fitbit app (from the MFP app--Fitbit prefers you use their app, which isn't bad, but MFP is a lot better). I have a Charge 2, officially outdated/no longer supported.

I'll buy a new one when it dies, but it still works fine.
Plus you have a great support group here to cheer you on. You can do it!