Low BP required the same amount of attention as does the high BP or even more than that. You need to have your tummy full all the time. Eat small sensible foods and by no chance indulge yourself in consuming high amount of Salt or salty foods. I can't prescribe you diet as I Need to have your diet history, medical history and lifestyle pattern in detail. As of now kindly consider these-
1- never be on empty stomach
2- have lots of fluids-lemon water, coconut water, lassi, chaz, etc
3- keep nuts by your side so that when ever you feel hungry you can consume them
4- fix up your meal timings
5- avoid too much of tea or coffee
6- no fasting until and unless unavoidable
Feel free to call me for a healthy lifestyle based diet.