My blood pressure was 146/97 this morning. Is this the danger zone or mildly high?

Heres a brief bit of info on me : 28yo woman, 5'3"-195lbs overweight, no real exercise program but my work routine incorporates walking a mile 4 days a week, formerly on high BP meds but stopped taking a few years ago. I'm willing to change my lifestyle(i.e. eating habits, weight, activity) because I realize this isnt going to go anywhere unless it is treated. Im worried because I think my feet are swollen and I am a little scared. I have a daughter, I want to be healthy...dont want to be one of these people keeling over dead from untreated health problems but because I FEEL ok and have been the same weight for like 8 years and honestly aside from the health problems dont have a problem with my weight. Im rambling .....but I hope u get the picture...Im basically asking where do you start in treating this...like an overall (limited meds) lifestyle change...any ideas?