Congrats; must feel nice to have someone finally know about it. And your uncle seems like he'd be the one to tell. A few of my closest friends smoke to quell their anxiety. Something to note would be that different strands of weed have different effects, and that its effect might change for you after awhile and increase your SA.
Oh, and it's always polite to decline with a simple "no thanks". I think it's impolite for someone to ask you twice consecutively or pressure you.
Your uncles heart was in the right place but pressuring you into smoking pot and drinking alcohol isn't cool, especially with SA as it could have triggered a bad episode, it's kind of a scumbag thing to do to pressure someone with social problems to smoke drugs and drink. I know some people think marijuana is the safest miracle drug in the world, but not everyone reacts that way some people can react very badly to it. I'm glad you had a good experience though. I would have loved to smoke pot and drink heavily with one of my relatives.
I used to get anxiety attacks when I smoked pot, but that was an everyday habit. I couldn't communicate because of the anxiety, the lump I used to get in my throat as well as the extreme dry-mouth. I quit for a couple of months, (using amphetamines as a replacement, stupid I know) then started smoking again a few days ago. It finally feels good to smoke weed again. Now I have this stupid amphetamine habit that I've got to kick.
And I know what you mean about revealing things when you're high, and then regretting saying the things you've said. Happens to me all the time when I'm on amphetamines, I spill my guts to ANYBODY even if they don't really need to hear it.