Sweet Tooth Running Rampant

I'm trying to change my eating habits and exercising, but my sweet tooth has been on a rampage lately, which is making it really hard to make healthier eating choices. The worst part is the cravings. And I don't have much room to exercise at home and I refuse to waste money on a gym membership because I know I'll never find the time nor the energy to go. I want to buy a bike, but my anxiety makes it hard for me to push it around the store to the checkout line without my mind screaming that everyone thinks it's weird that I'm rolling a bike to the front. What can I do to control my sweet tooth? I used to be able to easily say no to sugar, but it's been hard lately.