Re: I need some thoughts!
First of all, try and take a deep breath and relax. It definitely sounds like you're suffering from some form of anxiety, which I can definitely relate to. It's not fun! The shortness of breath and the paranoia are all definitely symptoms of anxiety. I'd recommend that you stay away from smoking any more weed. For some people, it calms them down, but for people with anxiety it can make them much more paranoid and anxious. It's a flip of the coin really what it does to you, but from your experience I definitely think it's a good idea to stay away from that.
I don't think you have to worry about a brain tumor; you'd be having other symptoms if that were the case. Try and let that go and focus on relaxing, getting a lot of sleep, eating properly and doing everything you can to stay healthy and keep away your anxiety. It might be a good idea to go and talk to a councillor if you're still feeling really anxious, they might have some more ideas on exercises you can try, or if it really comes down to it, anti-anxiety medications.