I began smoking weed at the age of 15(ish), after finding some of my step dads secret stash (with some porno - lol). After a night out camping, drinking and smoking weed and tobacco, I began smoking tobacco to bring about "some" of the relaxation I got from smoking weed.
After my Year 11 exams (I guess the end of high school for the US) my step dads plants were done drying, so I smoked weed daily with my mates through out the summer, stealing about an 8th a day (I mustve cost him alot, because as I have now learnt, he didnt actually smoke it, he sold it to his dealer friend).
I went to 6th Form (college) and smoked weed and cigarettes on a daily basis throughout. Thankfully I had enough common sense to lay off the weed during revision period or I almost definitely wouldnt have gotten into University. After my 6th Form exams (which I somehow passed) I took a gap year, getting a very stressful job with a telesales company for TalkTalk (who do terrible broadband - dont go with them).
The stress of this job, combined with the weed I was smoking at the time, and the weed I had been smoking for what was 4/5 years almost daily, and some bad genes (my uncle is a paranoid schitzophrenic) sent me on a downward spiral. I became paranoid of everyone, I thought I was being spied on by my parents, my friends were "definitely" involved and it was DEFINITELY not the weed causing this.
I tell you what, hearing every horrible thing youve ever done told to you in your parents voice, things they shouldnt know about, inside of your head is terrifying. Every time you have ever thought "I shouldnt have done that" or "why didnt I do that", and the voices of your parents are in your head saying "what a fucking idiot", "little piece of shit, cant even do ..." - Its horrible, and I genuinely with all my heart believed that they were actually doing it aswell.
I confronted my parents, and walked out a few times after telling them they were assholes for spying on me. They were actually very supportive, and this whole event helped me grow closer to them both. After getting a psychiatrist, and coming to some personal conclusions, I decided to stop smoking weed - and I did cold turkey. I also walked out on my job, which helped my stress levels immensely.
After quitting weed, my tobacco intake went up alot, but the paranoia went away mostly. I say mostly, because sometimes I still hear something faint (like another inner monologue, but less crazy sounding), but I now have the mindset to deal with it.
Now, Im 21 - I have just completed my first year of Games Technology at Uni (got a first and 5 2:1s) and am happier than Ive ever been in my life.
Thats my weed and tobacco story. I basically got screwed. I have learnt a hell of a lot about myself, and while I am at Uni, the guys I used to smoke weed with are sat in what is practically a squat, getting fucked on heavy drugs every night without a care in the world. I was lucky enough to get screwed by weed, and got out of that lifestyle.
To answer your other question, I smoke tobacco because it relaxes me. I had some anger issues before I started smoking, and either because of weed or tobacco they have stopped. Smoking also passes the time quite well. I feel that as long as I am happy that is what matters, and if something dangerous like smoking is what helps me be a nicer better person to those around me, then so be it.
I used to smoke weed, because there was nothing else to do. Nothing else was quite as interesting as a smoke up with my friends. I guess I was addicted to weed (as much as you can be psychologically addicted to something), and I was constantly trying to get back that first high, the feeling of complete contentment - nothing matters in the world, its just you and your friends on this huge planet, and nothing but you and them matter.
I very rarely drink. I dont enjoy getting drunk, I dont really enjoy the taste that much, and I hate the feeling the next day from getting drunk (which I do because I am a lightweight).
Many of the things people seem to do are socially related. I can say that smoking is a very social habit, as is smoking weed and drinking. Obviously there are exceptions to this, but generally I think alot of habits such as what drugs you use, whether you smoke, what clubs you go to drink at, come down to what your friends or your clique or your group or whatever like to do.
Despite this, I dont have a problem with people smoking weed around me, or doing any drugs around me. They can do what they want, as long as they dont try and push them on me.
If you have read this far then many many cookies for you! I apologise for the wall of text.
I only hope that you dont have to go through what I have, and if you have or are or will, then I hope all goes well for you.