First off, i would suggest talking to your GP about the clear signs of anxiety, depression and general helplessness you appear to be exhibiting. Like you, i feel alone despite having loving friends/family. I have found that marijuana can make you closed off to the world while it shows you your true, unadulterated self. You are young, and the sheer volume of emotion effervescing from you shows that even if you hadn't enclosed your age. I think that some people can become very sensitive when they smoke from a young age. This anxiety, paranoia, depression combo that you are juggling is not healthy. If what you say is not in the least bit fabricated i think you will benefit from seeking council from a psychiatrist. I have this same depressing outlook on life, what you really need is to take a step back and think why these people, i.e your family, friends and boyfriend hang around with you, and you'll find that the paranoia, anxiety is frivolous, these people are with you because they enjoy you.
my advice, if you want to kill yourself, f**k your predisposed mistrust of prescription drugs and get some antidepressants from the doctor. If the situation is the same regarding paranoia and anxiety then it may be attributed to warped thoughts, i have found mood gym - an Australian idea to be very helpful in determining where the world sucks and where its just you that thinks the world sucks. if this isn't for you, maybe some counseling.
Just don't smoke weed to make the paranoia go away, it exasperates the problem and just remember everybody is crazy in their own way, you need constant reassurance your loved ones still love you, I'm masochistic, at the end of the day, just don't let the bastards grind you down.
This sounds like an extreme form of GAD (Generalized Anxiety Disorder), but as what I went through, this will pass once you start realizing you can't control everything. When you let go of egoic control, you will find life to be much more doable. My suggestion is to start taking a lot of B-12, Niacin (b-3), and magnesium. You will thank me. I suggest this because I "had" those issues too. They all disappeared. I still am anxious sometimes (ADHD) but trust me, those natural pills will prove to be miraculous. It's not the weed. The weed is designed to open up your mental and physical energies. Yes, it often opens you up, and sometimes closes you up, but trust me, it isn't the problem. Try those over the counter vitamins and you will be fine. I suggest 4,000 mg of Niacin for the mental fatigue. I am not a doctor, but I have studied extensively, been through pharma meds too (they only made me unhealthy until I got off of them). And lastly, meditation is key. It saved my life. Start with Youtube "guided meditation" and move on to binaural beats, etc. It will clear the bad energies in no time, and you will easily be able to face your fears. Your BF will be very appreciative, trust me. I am also a spiritual healer, so I suggest you get a chakra cleansing. Your lower chakras, and especially your third eye is going through some messy distress. Find a local Japanese REiki practitioner. It is essential. Hope this helps.