What Causes Consistent BP Of 90/80?

Hello, Good day, I extracted a tooth on the 8th of December 2014, the Dental Nurse informed me that I had "baby blood pressure" which was 90/80..
I am not a lover of callaloo and liver and vegetables. In fact, I don't eat much vegetable and I don't eat tomato or ketchup.
I exercise frequently and I walk alot and drink water..
I am also slightly over weight.
I am 20 years old and I don't have any children.
I wouldn't say I have an active sex life..
Please help me!!!!

Desperate