Feeding Baby

I'm a FTM so no judgement here ladies. I am currently bf and only plan to do so until my lo is 6 mnths old. After that, I plan to start solids. Anyway, my question is, when I start solids/baby food at 6 months am I still required to give her a bottle of formula too? 
Please don't suggest bf for a longer time period. I would love to, but my schedule will just not permit. So its hard to maintain my supply. I work full time and only have a 20 minute break to pump once at work, can't have snacks/water throughout the day and barely pump out enough at home. 
THANK YOU ALL LADIES FOR YOUR KIND RESPONSES!! :)