It's been causing me a lot of anxiety recently. I get caught up in weird trains of thought where I can't stop obsessively thinking about how mammalian people are and how pointless everything is, and meanwhile people around me are trying to talk about stupid shit like, "Hey do you want to go out and drink tonight?" and I'm thinking, "My god man can't you people see how short and miserable life is?! What is there to drink to?!"
It's a funny substance haha. I've thought about its effects a fair amount.
Yeah obsessive negative thoughts I get those too (varies with changing environments). I think it's the stupid shit people talk about that you can't emphathise with, or find absolutely no importance in. I don't know if this is the case with you, but I've come to think that I drift into Fi when I puff, and Fe deteriorates and anything that is socially-related becomes a bloody task, it requires conscious effort, and generally I feel rather uncomfortable in social engagement, because I too, become socially retarded.
It's much easier and more relaxing to attempt to engage in meaningful conversation, or to express deep thought, but most people have no idea what you're on about. If someone is capable however, I feel much more at ease with meaningful (especially abstract) discussion, although sustaining it is difficult (which is stressful in itself); the boost in Ne and thus the lack of structure, and forgetting what you were even on about, is bound to get the person you were talking to, and yourself, confused, and the conversation will generally be fruitless and end in silence and confusion, followed by a clusterfuck of chaotic thought.
Otherwise, silence amongst others is perfect, minumum communication - that's liberating while stimulating and engaging with Se in any way e.g. music, trippy animations, sex, reading etc.
So, yeah, to conclude:
Imagine the clash of flying into self-awareness and being around others who demand attention in the external world. It's a Fi-Fe tug of war, and Fi is pulling much harder (this would most likely be in a situation where you aren't comfortable around the people, Fi feels exposed -> anxiety OR Fi focus being the cause of inability to socialize and this inability to effectively communicate causes stress, consequently leads to anxiety).
Or Ne is exploding, with a lack of Fe, driving you insane as your brain goes into thought overdrive and makes you feel energy deprived, and possibly anxious.
Or you just direct all your attention to Se related activities, although depending on the activity, this could lead to fatigue (especially if the activity is boring, which could lead to apathy followed by anxiety). You can't go wrong with music, though.
EDIT: Don't know how accurate any of that was, or just anxiety occurs because it stimulates negative emotions from a bad past experience of intoxication...?
I'm not sure if smoking by myself would be any better as far as the anxiety goes. Could just be the kind of weed I'm smoking I suppose.
I'm prone to anxiety smoking around others, but as explained, varies greatly.
Alone, on the other-hand, very rarely will I have a negative experience, I can't even recall one.
It would either be insightful (widened perception) or just pleasurable.
Favourite thing to do is to listen to music, close my eyes, and just let my imagination unfurl while generating vivid visual mental imagery in relation to the music.
Legalize please.
Weed is prefered alone. It makes me more truly INTP, in a much happier way. I lay down, thinking, coming up with the craziest ideas. I implement them, figure out what the effect would do if i were to try it. I listen to music, hear things i've never heard before, even tho i've listened to this song a dozen times. I'm dancing, smiling. I can think about things that would make me sad and uneasy, in a completely neutral, objective almost content mood. You have feelings and thoughts but it all feels good and natural.
Yes. This is good.
)) that it used to seriously alter my perceptions of time and distance (with some funny situtations ensuing). 
