I work as a Cashier at a Circle K and I have been gaining some weight lately.

I think it is because I drink to much Soda while I am at Work and during the day when I'm not at work.. I am wanting to start drinking water, but it makes me pee alot like every 20 mins or so when I drink water and it is kind of hard to run to the restroom when you are working alone for 8 hours.. has anyone been in this situation and what do you suggest?