The 130/90-140/100 range is not very high, and if you have reading in that range, I assume your 170/110 was caused by stress. Also, it's your diastolic pressure that is high, not so much your systolic. The other way would be worse.
The concerning part is that you are an alcoholic (your words) at the age of 27. That's far worse than a bit elevated blood pressure. And - it will increase your blood pressure. I wouldn't be surprised if that, along with your smoking and maybe a bad lifestyle (are you overweight?) is to blame.
Your testing has only revealed that your blood pressure hasn't damaged any organs, it hasn't been found a cause. Check your thyroids and your stress hormones, possibly (discuss it with your doctor). Quit drinking, quit smoking and start exercising, lose weight if you are overweight. Then your blood pressure should be fine if there is no underlying cause :)
It could be stress, it could be lack of exercise, it could be eating process foods. Or it might just be pain old genes.
Hey there sorry for hearing about your problems.
Note that even 2 readings might not be a good indication of your blood pressure status - especially because both were done at the hospital. I am surprise the doctor did not ask you to buy a blood pressure monitor to monitor you blood pressure at home. Doing that before the final diagnostic is highly recommended.
Certain foods, smoking, drinking and being overweight are factors that have been associated with an increase in blood pressure. It is important to note that you can beat this thing by changing your lifestyle, on your own or getting help. There are many professionals our there that can help you quit smoking/drinking, losing weight at no charge to you if they fail - you can find a few of them listed here: http://www.managing-high-blood-pressure.com/ways-to-lower-blood-pressure-2.html
Be careful when eating out for any foods sold atrestaurants etc...are not good for our blood pressure - Loaded with sodium
Goodluck