Hello,
I'm not a doctor but I have High BP since I was 17 (now i'm 23) and I will tell you some useful things. First of all, don't worry 142/78 is not bad. 142 is a little high but I'm sure it's high because of the stress, 78 is GREATTTTTTTT and I think that you don't need medication but you need to exercise 3 to 5 days a week 30 to 45 minutes. Eat a lot of fruit and vegetables and FORGET about adding salt to your food.
Omega 3, Garlic, Magnesium, Vitamin C supplements reduces blood pressure and protect your heart (I take all of them plus other supplements like Zinc) but it will take about 3 months to see results.
Don't forget exercise and diet are very important but also you will not see fast results. Don't worry about your blood pressure because when you worry more you will raise it more. When I was 17 I was measuring my blood pressure 10 times daily and I was going crazy, my doctor told me to stop that and take one read each week although it was not less than 140/90. So don't worry and try to relax by listening to music (try Thomas Newman) and if you don't have time try it at night before you sleep. Oh by the way, coffee can raise blood pressure too but this is vary from one person to another.
I think you can manage your blood pressure without medication for many years and maybe forever
Be happy your diastolic is 78 lol many of us wish to have it like that.
Thanks and good luck
Michael